Exchangeable integrated-wire balloon catheter

ABSTRACT

A balloon catheter includes a flexible small-diameter guide wire provided with an enlarged-diameter distal end portion, and a flexible elongated tubular shaft with at least one dual-function fluid-conducting lumen adapted to both receive the guide wire extending therethrough, and to communicate pressurized inflation fluid to a distal balloon of the catheter. A distal orifice of the catheter communicates with the balloon and is provided with selective valving means for releasably engaging sealingly with the enlarged distal end portion of the guide wire. Apparatus is disclosed for axially moving the guide wire to effect engagement and disengagement of the enlarged distal end portion with the selective valving means of the catheter shaft. A torquer device is also provided by means of which the guide wire may be rotated relative to the catheter shaft for steering of the guide wire along a vascular pathway. A distal end tapered portion of the catheter shaft provides protection for a joint of the guide wire assembly. The tubular shaft of the catheter may extend through the balloon to provide better pushability for the catheter, especially in versions which employ a comparatively limp material for the balloon. Several alternative constructions for the selective valving means of the catheter shaft and for the enlarged distal end portion of the guide wire assembly are presented.

RELATED APPLICATIONS

This application is a continuation-in-part of U.S. application Ser. No.07/970,581, filed on Oct. 22, 1992, now U.S. Pat. No. 5,364,354 which isa continuation-in-part of U.S. application Ser. No. 07/690,447, filed onApr. 24, 1991, now abandoned.

FIELD OF THE INVENTION

The present invention relates in general to the field of ballooncatheters employed in the treatment of vascular diseases. Moreparticularly, the present invention relates to a balloon catheterassembly which can be positioned quickly and easily for use in openingvascular stenoses, yet which also provides the additional advantage ofproviding for rapid balloon removal and replacement while retaining aguide wire in place across a treatment site to provide wire-guidedaccess of a subsequent larger balloon catheter, for example, to thestenotic lesion.

BACKGROUND OF THE INVENTION

Over the last decade the medical procedure known as angioplasty hasbecome widely accepted as a safe and effective method for treatingvarious types of vascular diseases. For example, angioplasty is widelyused for opening stenoses throughout the vascular system andparticularly for opening stenoses in coronary arteries. At present, themost common form of coronary angioplasty is called percutaneoustransluminal coronary angioplasty (PTCA). This procedure utilizes anelongate more or less flexible dilatation catheter having an inflatableballoon at its distal end. Using a fluoroscope and radiopaque dyes forvisualization, a physician may steer the distal end of the dilatationcatheter into position through a guide catheter and across the stenosis.Once so positioned, the dilatation balloon is inflated for a briefduration to open the artery and establish adequate blood flow.

Typically, inflation of the balloon is accomplished by supplyingpressurized fluid through an inflation lumen in the catheter. Thisinflation lumen is connected to an inflation apparatus, which includes asource of pressurized inflation fluid and is located outside thepatient's body. Conversely, applying a negative pressure to theinflation lumen collapses the balloon to its minimum dimension forremoval of the balloon catheter from within the target blood vessel.Such an application of negative pressure to the dilatation balloon isalso used to insure that the balloon has its minimal dimensions duringinsertion of the balloon to a treatment site.

In the past years a number of balloon catheter designs have beendeveloped which have contributed to the safety and acceptability of PTCAand similar medical procedures. The most common design is known as an"over-the-wire" balloon catheter. This conventional dual-lumen devicetypically utilizes a relatively large lumen for passage of a guide wireand injection of angiographic visualization dye to assist in theplacement of the device. A second parallel lumen is provided forinflation and deflation of the balloon. Typically, a steerable guidewire is positioned within the larger lumen and the entire assembly ismaneuvered into an initial position within the target artery through apreviously positioned guide catheter having an inner diameter ofappropriately larger size sufficient to pass the treatment catheter.Once near the site of the stenoses, the guide wire can be rotated andaxially extended or retracted into position across the lesion. Theballoon dilatation catheter is subsequently advanced along the guidewire to position its deflated balloon across the lesion. Inflation ofthe balloon effects dilation of the stenosis.

Though successful at opening stenotic lesions, these dual-lumencatheters are relatively bulky and stiff, which makes their usedifficult for any lesions except those that are proximal and localizedin non-tortuous, easily accessible vessels. Moreover, theseover-the-wire balloon catheters are of an early design, and require anadditional implanting physician or assistant to control the guide wireduring positioning of the assembly because movement of the catheter andguide wire are independent of one another. This complex coordinatedactivity requires both experience and skill, and may also result in aslower insertion procedure than is desired.

An alternative over-the-wire catheter assembly utilizes a non-removableguide wire that allows for longitudinal or axial movement. However, thisdesign has a significant drawback because the entire non-removable guidewire catheter assembly must be removed to accomplish replacement orexchange of the balloon. In some cases of PTCA it is necessary toreplace the balloon with one of different diameter or configurationfollowing the initial dilation. Additionally, cases of acute re-closurehave been noted where the lesion re-closes following dilation andremoval of the balloon catheter. This alternative over-the-wire systemadds to the difficulties of these subsequent procedures by requiringthat the replacement catheter renegotiate the entire placement vascularpath without the advantage of a retained guide wire position. That is,when the catheter is pulled out to allow a catheter exchange, the pathto the treatment site is at least partially lost because the guide wirecomes out with the catheter assembly.

Another version of conventional balloon dilatation catheters are knownas, "mono-rail" variants of the standard balloon-on-a-wire system, andhave been developed so that only a distal portion of the ballooncatheter tracks over the guide wire. These mono-rail catheter systemsutilize a conventional inflation lumen and a relatively short guiding orthrough lumen for the guide wire at the distal end of the catheter. Theprincipal benefits of the mono-rail variant of balloon dilatationcatheter is the reduction of frictional drag over the length of theguide wire, which is external of the catheter over much of the length ofthe catheter, and the ease of balloon exchange. The mono-rail cathetersprovide the ability to recross an acutely closed vessel or to exchangeballoons without removing or extending the guide wire. However, adisadvantage of this design is the increased difficulty in steering theguide wire because this guide wire is not supported by the ballooncatheter itself. Additionally, the mono-rail catheters are at least ofdual lumen configuration at their distal ends, and this design producesa larger profile for the catheter and a larger shaft size.

Another conventional balloon dilatation catheter design is the"fixed-wire" or integrated "balloon-on-a-wire" dilatation catheter.These single-lumen designs utilize a relatively small guide wirediameter positioned within an inflation lumen and permanently fixed tothe distal end of the dilatation balloon. This design produces alow-profile assembly which is able to cross severely narrowed lesionsand to navigate tortuous vascular pathways. Additionally, the fixedguide wire is bonded at the distal end of the balloon, and improves thesteerability and pushability of these designs. This aspect of thefixed-wire catheters also enhances their maneuverability. The thin shaftdesign of these catheters also improves coronary visualization, andenables all but the tightest critical lesions to be crossed. However,although able to provide relatively quick and simple balloon placement,as well as providing access to lesions otherwise unsuitable for PTCA,balloon-on-a-wire systems sacrifice both the ability to maintain guidewire position across the lesion when exchanging balloons, and also thesafety advantage of being able to recross an acutely closed vesselwithout repositioning the entire assembly.

SUMMARY OF THE INVENTION

In view of the deficiencies of the conventional technology, it is anobject for the present invention to provide a balloon-on-a-wiredilatation catheter which incorporates all of the benefits of a smalldiameter fixed-wire system yet allows for removal, reengagement orreplacement of the balloon while leaving the guide wire in place topreserve an easily renegotiated path along the blood vessel beingtreated.

An additional object of the present invention is to provide anintegrated-wire dilatation catheter offering an extremely low profileand a small shaft size to facilitate maneuverability and placement ofthe catheter as well as to provide the catheter with the ability tonegotiate tortuous vessels and to pass highly stenosed lesions.

A further object of the present invention is to provide anintegrated-wire balloon catheter having a steerable guide wirereleasably fixed inside the catheter to provide enhanced torqueability,pushability, and maneuverability in order to facilitate the rapid,single operator placement and positioning of the catheter assembly.

Yet a further object of the present invention is to provide aballoon-on-a-wire dilatation catheter which allows for removal,reengagement or replacement of the guide wire while using the samecatheter.

It is yet a further object of the present invention to provide anintegrated-wire balloon catheter which meets the above-identifiedobjects yet may be used in embolectomy applications for treatment ofvascular lesions.

Another object for the present invention is to provide such a catheterassembly which includes an enlarged distal section of the guide wireforming in cooperation with a distal sleeve portion of the cathetershaft a valving device which may be selectively opened and closed byaxial relative movement of the guide wire.

Still another object for the present invention is to provide in such avalved catheter assembly a radiopaque marker which serves the dualfunction of proximally positioning an inner sleeve member on the guidewire, which inner sleeve member serves to define the enlarged distalvalving section of the guide wire, and of providing a feature which aphysician may visualize with a fluoroscope to determine the opened orclosed condition of the valving device.

Yet another object for the present invention is to provide such acatheter assembly in which the inner sleeve member on the guide wiredistal end is formed on this guide wire in such a way as to essentiallyeliminate leakage of pressurized fluid at the interface of the wire andsleeve member and yet still allow relative rotation of this sleevemember on the wire.

Another object for the present invention is to provide such a catheterassembly also having a torquer assembly for grasping and twisting theguide wire so as to assist in steering this wire along a vascularpathway. The torquer assembly is especially configured to allowdistal-end insertion of the guide wire into the catheter shaft byfacilitating passage of the guide wire through the proximally-disposedtorquer assembly.

Still another object for this invention is to provide such a catheterassembly also having a guide wire disengagement device locatedproximally of the catheter assembly and engageable with the guide wirefor axially moving the guide wire relative to the catheter shaft inorder to open and close the valving device at the distal balloon of thecatheter.

These and other objects are achieved by the exchangeable integrated-wireballoon catheter of the present invention which, in accordance withbroad structural aspects thereof, includes at least a single-lumenballoon catheter assembly having an outer sleevelike seal sectionadjacent to its distal end, which seal section releasably engages anenlarged distal end portion of a flexible guide wire running the lengthof the catheter assembly. This unique construction allows rotational andlongitudinal movement of the guide wire relative to the balloon catheterwhere desired and, if necessary, allows the catheter to be removed andreengaged or fully exchanged over the guide wire. Further, additionallumens may be incorporated into the basic catheter design to carrydrugs, blood, fluids and the like or to allow blood to passively perfusethe distal artery during balloon inflation.

More specifically, the flexible guide wire of the present invention isformed of metal, polymeric material or a combination of both and isprovided with a relative small cross-sectional diameter to increase itsflexibility and to reduce the overall cross-sectional profile of thedilatation catheter assembly. However, unlike conventional guide wiredesigns, the distal end portion of the present inventive guide wiresteps up to an enlarged outer diameter.

The catheter assembly according to a first preferred embodiment of thepresent invention positions a small diameter proximal portion of theguide wire along the length of an axial lumen of an elongated tubularshaft of the balloon catheter and through the balloon itself. Theexpandable balloon portion of the catheter is connected to the distalend of the tubular shaft in a sealing or fluid conducting arrangementwith the axial lumen. The distal end of the expandable balloon isprovided with an orifice that is coaxially aligned with the axial lumenand adapted to receive or conduct the guide wire. The distal orifice inturn is provided with means for releasably engaging the enlargeddiameter distal end portion of the guide wire in a sealing relationshipto allow for pressurization and inflation of the balloon and to fix thewire within the catheter in order to facilitate maneuvering the assemblyduring placement.

In the catheter assembly according to a second preferred embodiment, thetubular shaft extends through the length of the balloon. The distal endof the tubular shaft in turn is provided with means for releasablyengaging the enlarged diameter distal end portion of the guide wire in asealing relationship, as specified for the first embodiment. Theproximal end of the balloon is attached to the tubular shaft, and atleast one slot is provided in the tubular shaft at about the mid-portionof the balloon to allow inflation fluid to be delivered from the axiallumen to inflate the balloon.

In this manner, the present invention combines the functions of fluidconducting and guide wire transmittal in a single lumen as opposed tothe prior art dual-lumen balloon catheter designs. These uniqueconstructions provide an exchangeable balloon catheter having anexceptionally small insertion profile and all of the advantagespreviously associated with non-exchangeable fixed-wire catheters; yetthey also provide the advantage of the ability to leave the guide wirein position across a vascular lesion during balloon exchange or removal.

In the first preferred embodiment of the present invention the means forreleasably engaging the enlarged diameter distal end portion of theguide wire in sealing relationship is a resilient sleeve which extendsfrom the distal orifice of the expandable balloon. This sleeve isdimensioned to slide over and extend distally beyond the enlargeddiameter distal end portion of the guide wire as the catheter isadvanced distally along the wire. Preferably, the distal portion of thewire is formed to have a smoothly surfaced, round cylindrical crosssection as this construction allows the resilient sleeve to seal againstthe distal end portion of the guide wire. Additionally, it providessufficient freedom of movement to allow the guide wire to rotate inplace in order to facilitate the manipulation of the balloon catheterinto position within a vascular pathway.

The means for releasably engaging the enlarged diameter distal endportion of the guide wire in sealing relationship according to thesecond preferred embodiment includes a resilient sleeve which extendsfrom the distal end of the expandable balloon. This sleeve is attachedto the distal end of the tubular shaft which is dimensioned to slideover and extend distally beyond the enlarged diameter distal end portionof the guide wire as the catheter is advanced distally along the wire.

Sliding the catheter proximally relative to the internal guide wire (orvice versa) slips the resilient sleeve off of the enlarged diameterdistal end portion of the guide wire onto the smaller diameter proximalportion of the wire. The unseating of the resilient sleeve or thetubular shaft from the enlarged diameter distal end portion of the guidewire breaks the seal at the distal catheter end. In this position theguide wire can be advanced axially along the longitudinal axis of thecatheter to cross narrow or irregular lesions or to follow a tortuousvascular pathway. Similarly, following dilatation the guide wire can beleft in place across the stenotic lesion as the disengaged balloon ispartially withdrawn along the wire to verify dilation of the stenosis,and restored blood flow.

If necessary, the balloon can be advanced again distally along the wireuntil the resilient sleeve or tubular shaft sealingly reengages thedistal end portion of the guide wire. Following reengagement the ballooncan be re-inflated. As those skilled in the art will appreciate, acomplete exchange of the balloon is possible without loss of the trackback to the treatment site utilizing the same general procedure alongthe positioned guide wire.

The embodiments according to the present invention may be adapted foruse as an embolectomy catheter assembly, the only difference being thata balloon having a different material is provided in place of theflexible balloon typically used in angioplasty procedures.

To facilitate visualization of the guide wire and balloon catheterduring the procedure, the apparatus of the present invention ispreferably provided with one or more radiopaque markers. Typically,these markers are formed of small coils, strips or spheres of gold,platinum or other dense, relatively inert metal. In one embodiment ofthe present invention a radiopaque spring coil of flexible wire isprovided distally to the enlarged diameter distal end portion of theguide wire. Similarly, in alternative embodiments of the presentinvention radiopaque markers are located along the guide wire atpositions proximal to the enlarged distal end portion of the wire. It isalso contemplated as being within the scope of the present invention toposition radiopaque markers on the balloon catheter to enable thecoronary physician to visualize the placement of the balloon relative tothe guide wire and stenotic lesion.

Another version of the present inventive balloon catheter assemblyincludes a torquer located proximally of the catheter shaft andselectively engaging the guide wire for twisting this wire to effectsteering of the guide wire along a vascular pathway. The torquerincludes a feature particularly improving ease of guide wire passagethrough this torquer so that initial guide wire loading into thecatheter assembly as well as catheter exchange over a positioned guidewire are improved.

The catheter assembly may also include a disengagement device engageablewith the guide wire to effect axial movements of this guide wirerelative to the catheter shaft. Thus, disengagement and reengagement ofthe enlarged distal valving sleeve with the outer sleevelike valvingportion of the catheter shaft is facilitated by the disengagementdevice.

Also, the catheter assembly may include on the guide wire assembly, avalving sleeve member so formed as to be relatively rotational on theguide wire distal end portion, and yet which essentially offers zeroleakage of pressurized fluid for balloon inflation at the interface ofthe sleeve member and guide wire. This essentially zero leakage aspectof the present invention may be important because the volume of aninflated dilatation or embolectomy balloon is not very great and thedelivery of pressurized inflation fluid to these balloons is effectedalong a long narrow passage way or inflation lumen which may effect asignificant pressure loss. Under these conditions, even a small loss ofpressurized fluid at the valving device can adversely affect theforceful inflation effected at the balloon for therapeutic purposes.

Other features, objects, and advantages of the present invention willbecome apparent from a reading of the following detailed description,taken in conjunction with the accompanying drawing Figures whichillustrate, merely by way of example, the principals of the presentinvention, and in which the same reference numeral refers to the samefeature, or to features which are analogous in structure or function.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a fragmentary elevation view of an integrated-wire dilatationcatheter embodying the present invention;

FIG. 2 provides an enlarged cross-sectional view of an encircled distalportion of the balloon catheter seen in FIG. 1;

FIG. 2A is an enlarged cross-sectional view, similar to FIG. 2, of adistal portion of a second embodiment of a balloon catheter;

FIG. 2B provides an enlarged cross-sectional view, similar to FIGS. 2and 2a, of the distal portion of yet another alternative embodiment of aballoon catheter;

FIG. 3 is a partial cross sectional view of a distal portion of theballoon catheter of FIGS. 1 and 2, and is shown in a collapsed ordeflated operative position;

FIG. 4 presents a sectional view of the distal portion of an alternativeembodiment of the present invention illustrating additional featuresthereof;

FIG. 4A is a sectional view of the distal portion of another alternativeembodiment of the present invention illustrating additional featuresthereof;

FIG. 5 is an enlarged partial sectional view of an alternativeembodiment of the distal portion of a guide wire usable in the ballooncatheter of FIG. 1;

FIG. 5A is an enlarged partial sectional view of another alternativeembodiment of the distal portion of a guide wire for the ballooncatheter of FIG. 1;

FIG. 6 is an enlarged cross-sectional view of the distal end portion ofa replacement balloon catheter illustrating additional features of thepresent invention;

FIG. 7 is a cross section of the balloon catheter of FIG. 6 taken alongthe line 7--7;

FIG. 8 is an enlarged sectional view of the replacement balloon catheterof FIG. 7 minus its packaging mandrel and cover;

FIG. 9 is a partial fragmentary view of an alternative guide wireillustrating additional features of the present invention;

FIG. 10 is an enlarged cross-sectional view of the distal portion of analternative dual-lumen balloon catheter illustrating additional featuresof the present invention;

FIG. 11 is an enlarged cross-sectional view of the distal portion of analternative dual-lumen balloon catheter illustrating additional featuresof the present invention;

FIG. 12 provides a fragmentary cross sectional view of yet anotheralternative embodiment for a distal end portion of a guide wire for usewith the catheter assembly of the present invention;

FIG. 13 presents a fragmentary cross sectional view of a torquer portionof a proximal Y-connector of the catheter assembly seen in FIG. 1;

FIG. 14 is a fragmentary side elevation view of an alternativeembodiment of the catheter assembly according to the present invention;

FIG. 15 presents a fragmentary cross sectional view of yet anotheralternative embodiment of the present catheter assembly in which aproximal Y-connector also includes a disengagement device for grippingand axially relatively moving the guide wire of the catheter assembly;

FIG. 16 provides a fragmentary plan view of the disengagement deviceportion of the catheter assembly fragmentarily seen in FIG. 15; and

FIGS. 17-26 depict fragmentary cross sectional views of alternativeembodiments of the invention;

FIGS. 27 and 28 provide fragmentary cross sectional views of yet anotherembodiment of the invention;

FIGS. 29 and 30 present yet another alternative embodiment of theinvention;

FIGS. 31 and 32 respectively present two more alternative embodiments ofthe invention; and

FIGS. 33 and 34 respectively depict two additional alternativeembodiments of the invention, which are similar in several respects bothto one another and to the embodiments of FIGS. 18 and 25, and also tothe embodiment of FIG. 31.

DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENTS OF THE INVENTION

Referring to the drawing Figures, FIG. 1 shows an elongate ballooncatheter assembly, which is generally referenced with the numeral 10.The balloon catheter assembly 10 includes a proximal Y-connector,generally indicated by reference numeral 12. Catheter assembly 10 alsoincludes an elongate tubular and flexible shaft portion 14, whichterminates at a distal end 16. Adjacent to the distal end 16, the shaftportion 14 carries an expansible dilatation balloon 18. The catheterassembly 10 including Y-connector 12, is provided with a through passageor lumen (not seen in FIG. 1, but hereinafter generally referenced withthe numeral 20) opening proximally on the Y-connector and distally atthe distal end 16.

Through this lumen 20 passes an elongate guide wire assembly, generallyreferenced with the numeral 22. A proximal portion 24, and a distalportion 26, of the guide wire assembly 22 are seen extending from theY-connector 12 and from the distal end 16, respectively, in FIG. 1. Theguide wire assembly 22, as will be seen, is slidably movable through thelumen 20 of the catheter assembly 10, and is also removably engageablein a sealing relation with the catheter assembly 10 for purposes ofinflating balloon 18. In order to effect the inflation of balloon 18,the catheter assembly 10 includes at Y-connector 12 an inflation port 28which communicates with the balloon 18 via the lumen 20.

A hemostatic seal 30 is provided at the proximal end of the Y-connectorto prevent fluid leakage around the guide wire 22. Preferably, the seal30 is adjustable or releasable to facilitate the removal or exchange ofthe catheter assembly 10 from around the guide wire assembly 22, andalso to facilitate removal of the guide wire 22 from within the catheterassembly 10.

Though not essential to the practice of the present invention, a torqueror drum 32 is associated with the Y-connector 12 and provides aphysician with the ability to rotate the guide wire assembly relative tothe catheter assembly. This rotation of the guide wire is manifest atthe distal end portion 26, and may assist in steering the guide wire andcatheter assembly 10 through a vascular pathway.

A compression or flare fitting 34 sealingly connects the shaft portion14 of the catheter assembly 10 to the Y-connector 12. Distally from thefitting 34, the catheter assembly 10 may include also one or more strainrelief members 36a, 36b, etc., sheathing the catheter shaft 14 over aportion of its length.

More particularly, viewing FIG. 1, the catheter assembly 10 includes anelongate tubular body 38 which is sealingly coupled to the Y-connector12 in the fitting 34, and which alternatively extends either to theballoon 18, or to the distal end 16 while externally carrying balloon18. Preferably, the tubular body 38 is formed of a polymeric materialsuch as polyethylene, polyamide, polyimide, polypropylene,polyvinylchloride, polyester such as polyethyleneterephthalate (PET), orpolyolefin copolymer. Additionally, body 38 may be coated with afluoropolymer (such as PTFE), silicone or other materials including lowfriction lubricants. Alternatively, a proximal portion of the cathetershaft may be formed of fine-dimension metallic tubing (hypo tube). Thishypo tube would be formed of stainless steel.

Adjacent to the distal end 16, the tubular body 38 of catheter shaft 14carries the expansible dilatation balloon 18, which is shown inflated inFIG. 1 and the details of which are more readily apparent in theenlarged cross section of FIG. 2. As shown in FIG. 2, dilatation balloon18 is formed as an integral part of catheter assembly 10 in fluidconducting communication with a single, axial lumen 20 runningthroughout the length of tubular body 38. Though the integralconstruction of catheter 10 illustrated may be preferred, alternativeconstructions may be utilized so long as dilatation balloon 18 issealingly connected to the tubular body 38 adjacent to the distal end 16of the catheter shaft assembly 14.

Accordingly, dilatation balloon 18 may be constructed of the same ordifferent polymeric materials utilized in the construction of tubularbody 38. Similarly, low friction coatings such as fluoropolymer(including, for example polytetrafluoroethylene (PTFE), generally knownas "Teflon") or hydrophilic materials and lubricants (such as silicone)may be utilized to enhance the low-friction relative movements of allcomponents of catheter assembly 10 during angioplasty or embolectomy.

Balloon 18 is provided with a distal orifice 40 which is coaxiallyaligned with lumen 20 and adapted to receive and conduct guide wire 22.As mentioned above, this guide wire 22 extends throughout the length ofcatheter assembly 10 including the balloon 18 and beyond distal end 16via the distal orifice 40. Orifice 40 is provided with means forreleasably engaging guide wire 22 in a sealing relationship. That is,the guide wire assembly 22 and catheter assembly 10 are configuredcooperatively to define a valving device at the orifice 40, whichvalving device is generally referenced with the numeral 41, and whichvalving device 41 is responsive to relative axial movement of thecatheter and guide wire assemblies to control fluid flow through theorifice 40. In the exemplary embodiment of the present invention, thismeans for releasably engaging in sealing relationship at orifice 40(valving device 41) is formed of a resilient sleeve 42 which extendsfrom distal orifice 40 and is dimensioned to slidingly engage anenlarged-diameter distal end valving portion (in the distal end portion26) of the guide wire 22, which enlarged-diameter distal end valvingportion is generally referenced with the numeral 44.

This enlarged distal end portion 44 includes a cylindrical collar 46which is sealingly coupled to guide wire 22. Resilient sleeve 42 may beformed from the same material forming the remainder of tubular body 38or may be formed from a lubricous polymeric material, or of othermaterial. Alternatively, resilient sleeve 42 may be coated along itsinner surface with a lubricous material to facilitate its engagementwith cylindrical collar 46. Cylindrical collar 46 can be formed of awide variety of materials ranging from stainless steel to polymericmaterials and natural or synthetic gemstone, and may even be formed asan integral part of wire 22. However, it is preferred that collar 46 beformed of or coated with a polymeric material such as PVC, polyamide,polyimide, or fluoropolymer such as polytetrafluoroethylene (PTFE) asthese materials provide an added degree of flexibility distal endportion of the guide wire which is formed by collar 46 and is ofenlarged cross-sectional diameter. It is also preferred that the collarportion 46 may be formed of synthetic gemstone, with the sleeve portion42 having a shape-conformal coating of elastic or resilient polymer onits inner surface for sealing cooperation with this gemstone valvingmember. An additional advantage of forming collar 46 from materials suchas PTFE is that this cylindrical collar 46 may be sealingly coupled toguide wire 22 yet retain the ability to slide axially along guide wire22, and to allow the guide wire 22 to be rotated inside the collar 46.When the collar member 46 is formed of gemstone, the surface of thecollar member is highly polished, and rotational freedom of the guidewire assembly 22 is achieved simply by sliding this polished surfacerelative to the inner surface of the sleeve 42, while still maintaininga sealing engagement therewith.

Though not essential to the practice of the present invention, guidewire 22 is preferably provided with a flexible spring coil 48 positioneddistally to the enlarged diameter cylindrical collar 46. The spring coil48 is joined to the guide wire assembly 22 by means of a metallic braze49, such as soldering or brazing. As shown in FIGS. 2-5, spring coil 48is preferably provided with a smooth hemispherical tip 50 in order toreduce vascular trauma as guide wire 22 is advanced along a vascularpathway. Spring coil 48 may be formed of any resilient material,preferably metal, and in the preferred embodiment of the presentinvention is formed of a radiopaque material such as platinum or gold.Thus, spring coil 48 functions as an additional marker to assist thecoronary physician in positioning the apparatus of the presentinvention.

For example, when spring coil 48 has been advanced to a position justbeyond the target lesion the physician may be comfortable in knowingthat balloon 18 is properly positioned across the lesion. At that point,as long as resilient sleeve 42 is sealingly engaging cylindrical collar46, then balloon 18 may be inflated by pumping a pressurized fluid, suchas saline or contrast medium, into inflation port 28 and along axiallumen 20. Following dilation of the stenosis, a negative pressure can beapplied to port 28 and axial lumen 20 to delate balloon 18 prior to itsremoval from the lesion.

Though spring coil 48 is illustrated in FIGS. 2-5 as being relativelystraight, it is commonly known in the art to pre-curve spring coil 48 sothat the implanting physician can rotate wire 22 and direct tip 50 ofwire coil 48 into specific vascular junctions to direct the entirecatheter assembly 10 along a selected vascular pathway. Rotationalmanipulation of wire 22, or "torquing" as it is referred to in the art,is accomplished by rotating torquer 32 of Y-connector 12. As will befurther explained, this torquer firmly clamps wire 22. The axiallyresilient construction of guide wire 22 transmits this torque along theentire longitudinal extent of wire 22 to coil 48.

However, because cylindrical collar 46 is preferably sealingly coupledto guide wire 22 in a rotatable manner, this torque is not transmittedto balloon 18 and prevents this balloon from wrapping in a spiralfashion around guide wire 22. Alternatively, where cylindrical collar 46is not rotationally free relative to the wire 22, it is preferred thatthe outer surface of this cylindrical collar 46 be very smooth to allowa certain degree of slippage between it and the inner surface of theresilient sleeve 42. In this manner, balloon wrapping also can beprevented.

In this depicted embodiment of the present invention the cylindricalcollar 46 is coupled to the guide wire 22 by using one of severalmethods. In a first method, a pre-extruded teflon tube of selecteddiameter representing the collar 46 is slid in a proximal direction overthe guide wire 22 and beyond the distal tip 50. The coil 48 is thenbrazed to the distal tip of the guide wire 22 keep the collar 46 inplace. In a second method, a piece of teflon shrink tubing representingthe collar 46 is slid over the guide wire 22 and the coil 48 attached tothe tip of the guide wire 22. The collar 46 is then slid in a distaldirection over the joint and the tubing is heated to shrink the teflontubing against the guide wire 22.

Referring to FIG. 2, the cylindrical collar 46 is preferably locatedinside the resilient sleeve 42 so that the sleeve 42 extends distallybeyond the collar 46 by about 0.005 to 0.025 inches. This configurationprovides a stress relief because the transition between the collar 46and the flexible spring coil 48 is protected inside the sleeve 42. Thisstress relief feature minimizes any kinking of the guide wire 22 at thistransition. The sleeve 42 is externally buffed to produce a chamfer ortaper 52 (by, for example, grinding) to create a smooth transitionaltapered surface to aid in the atraumatic tracking of the selectedvessel.

As shown in FIG. 2, to retain polymeric cylindrical collar 46 inposition along guide wire 22, one or more retaining beads 54 and 56 maybe soldered or brazed to guide wire 22. Alternatively, adhesives or asimple mechanical fit (i.e., an interference fit of the beads on thewire 22) may be utilized to retain the axial position of the collar 46on the wire 22. It should also be noted that guide wire 22 andspecifically cylindrical collar 46, may be formed from a lubricouspolymeric material or provided with a thin coating of silicone,fluoropolymer or the like to increase its lubricity. This exemplaryconstruction produces a releasably engaging seal which fixes guide wire22 in position relative to balloon 18 yet allows guide wire 22 to berotated freely without wrapping balloon 18 about the shaft of guide wire22. Carried on the guide wire 22 and centered in the balloon 18 when thecollar 46 is centered in the sleeve 42 to close the orifice 40, is acoil of radiopaque wire wrapping 57. This coil 57 serves as a marker forthe physician who can center this marker at a stenosis to be dilatedprior to inflating the balloon 18, as is further explained below withrespect to the uses of this and other markers of the various catheterassembly embodiments.

In FIG. 3, balloon 18 has been deflated and retracted proximally alongguide wire 22 to a position where resilient sleeve 42 has completelydisengaged from cylindrical collar 46. It is important to note that, asshown in FIGS. 2 and 3, all portions of guide wire 22 proximal to itsenlarged diameter distal end portion (formed by cylindrical collar 46)have a cross-sectional diameter smaller than that of the outer diameterof collar 46. This construction allows the balloon catheter of thepresent invention to be completely advanced or retracted along theentire longitudinal extent of guide wire 22 for the purposes of balloonmanipulation, removal or replacement.

Thus, the balloon catheter can be replaced with a catheter having aballoon provided with a different expandable diameter if necessary toreopen a particularly difficult stenotic lesion. Similarly, if problemsdevelop with the inflation of balloon 18 during angioplasty it ispossible to replace the balloon with a properly functioning device. Allthe vascular physician need do is to retract tubular body 38 and balloon18 along guide wire 22 leaving guide wire 22 in position across thetarget lesion. Then, a replacement balloon can be advanced along thepositioned guide wire without having to retrace the entire vascularpathway.

As those skilled in art will appreciate, this greatly facilitates thespeed and safety of such a procedure. In order to reengage the balloonon collar 46 the vascular physician simply advances the catheter alongguide wire 22 to slide resilient sleeve 42 over cylindrical collar 46.Generally, in practice, when easy advancement of resilient sleeve 42relative to collar 46 ceases, the physician can be sure that a sealingengagement between collar 46 and sleeve 42 has been achieved. Thephysician need not achieve full or relatively centered positionalrelationship of the sleeve 42 and collar 46 as is shown in FIG. 2.Generally, it is sufficient merely that the physician feel thefrictional engagement of the collar into the sleeve. The completeengagement shown in FIG. 2 is for purposes of illustration only.

An alternative exemplary embodiment of the inventive catheter assemblyis shown in FIG. 2A. In order to obtain reference numerals for use indescribing the structure of this alternative embodiment, features whichare the same or are analogous in structure or function to those depictedand described above, are referenced with the same numeral usedpreviously. Viewing FIG. 2A, the distal end 58 of the tubular body 38extends from the proximal end of the balloon 18 also through the lengthof the balloon, and distally of this balloon structure to define anequivalent to the resilient sleeve 42.

The tubular body 38 is bonded to the balloon 18 at a distal bond 60, andto the proximal end 62 of the balloon 18 at a proximal bond 64. Thebonding is achieved by heat or adhesive bonding. In this embodiment, itis the distal end 58 of the tubular body 38 that is dimensioned toslidingly engage the cylindrical collar 46. The distal end 58 and thetubular body 38 are preferably made from a flexible material, preferablypolyethylene. Alternatively, other materials and plastics may be usedfor the distal end 58, but the proximal end of the tubular body can beformed of metallic hypo-tube bonded to a distal end polymeric portion ofthe tubular body 38 in order to provide optimal pushability for thecatheter assembly 10. The distal end 58 of the tubular body 38 extendsbeyond the collar 46 so that the collar 46 is located within the distalextension of this tubular body. Again, this proximal recessing of thecollar 46 protects the transition between the guide wire 22 and the coil48 from kinking. A taper 52 is provided at distal end 58.

Since the tubular body 38 extends the length of the balloon 18, theaxial lumen 20 of the body 38 likewise extends across the length of theballoon 18 and terminates at the sleeve 42. Tubular body 38 is providedwith one or more inflation slots 66 cut about 90-180 degrees apart fromeach other, and through which inflation fluid may be injected into theballoon 18. The slots 66 are preferably cut in the tubular body 38 atthe mid-portion of the balloon 18 to facilitate uniform expansion ofthis balloon. Also, any number of inflation slots 66 may be providedwithout departing from the spirit and the scope of the presentinvention. If one inflation slot 66 is used, it is also possible toextend the length of the slot 66 across the length of the balloon 18from the proximal bond 64 to the distal bond 60.

Thus, extending the tubular body 38 through the balloon 18 to form thesleeve feature 42 improves the manufacturability of the balloon catheterassembly 10, and also improves its performance during use by easing theengagement and disengagement of the guide wire 22. Further, the doublebonding provided by the proximal and distal bonds 64 and 60 supports theballoon 18 from disengaging during balloon inflation, and supports theballoon structure during catheter exchange.

Referring to FIG. 2B, another alternative embodiment of the presentinventive catheter assembly is illustrated. Again, in order to obtainreference numerals for use in describing the depicted structure,features which are the same or analogous in structure or function tofeatures depicted and described above are referenced with the samenumeral used above. In the embodiment of the invention depicted in FIG.2B, the tubular body 38 is enlarged proximal of the point 68. That is,at the point 68, the tubular body 38 is necked down to distally of thepoint 68 define the sleeve feature 42. Such proximal enlargement of thediameter of the tubular body 38 relative to its distal size allows forsmoother and easier guide wire and catheter exchange.

While the balloon catheter assembly of the present invention has beendescribed above in connection with a dilatation catheter, an embolectomyballoon catheter assembly may also be provided in accordance with theabove description without departing from the spirit and scope thereof.The embolectomy balloon catheter assembly is preferably made inaccordance with the embodiment of FIG. 2A, with two modifications orrequirements. First, the balloon 18 is made from latex, kraton orsilicone instead of from a polymeric material. Second, the distal andproximal bonds 60 and 64 are preferably bonded by adhesive bonding, heatbonding or other conventional means. Also, for an embolectomy catheterhaving a latex balloon, it is preferable to provide thread, andpreferably dacron, windings 70 around the distal and proximal bonds 60and 64, with a urethane coating 72 applied over the windings 70.

Additionally, as shown in the alternative embodiment of the presentinvention illustrated in FIG. 4, the retaining beads 54 and 56 may besoldered to the guide wire 22 somewhat proximally to the distal locationof cylindrical collar 46. The collar 46 is thus provided with an addeddegree of sliding axial movement along guide wire 22. This added axialmovement for the collar 46 on the guide wire 22 allows the positioningphysician to extend or retract the distal end portion 26 of the guidewire relative to the balloon 18 where necessary while still retainingthe seal between collar 46 and sleeve 42. It should be noted thatretaining beads 54 and 56 create an outer diameter which is larger thanthe inner diameter of cylindrical collar 46 yet smaller than the outerdiameter this collar.

In the alternative embodiment of the present invention shown in FIG. 4the radiopaque markers formed by marker 57 and spring coil 48 arearranged in what is known as a "book end" position. That is, the marker57 is placed at the proximal end of the balloon 18 and the marker 48 isadjacent to the distal end of this balloon. In this configuration theimplanting physician positions guide wire 22 such that spring coil 48 isdistal to the target lesion and radiopaque marker 57 is proximal to thetarget lesion. In this manner, balloon 18 is positioned across thelesion. Additionally, in accordance with the teachings of the presentinvention catheter 10 itself can be provided with an additionalradiopaque marker such as radiopaque ring 74, which is preferably ametallic band, such as platinum, for example, affixed to distal end 58of tubular body 38. Radiopaque ring 74 enables the vascular physician toconfirm that balloon 18 is properly positioned relative to collar 46 bylining up radiopaque ring 74 with radiopaque marker 57. This may beparticularly helpful during reengagement of sleeve 42 with cylindricalcollar 46.

In an alternative embodiment illustrated in FIG. 4A, the radiopaque ringmarker 74 is encapsulated between the distal end 58 of the tubular body38 and the proximal end 62 of the balloon 18. The proximal end of theballoon 18 is heat shrunk to the tubular body 38, simultaneouslycreating a seal between the balloon 18 and the body 38, andencapsulating the ring marker 74. The encapsulation process is performedwith a mandrel placed through the axial lumen 20 to provide a smoothinner surface for the lumen 20 and to ensure that the diameter of thelumen 20 remains constant around the encapsulation zone. It will beappreciated that the ring 74 can also be encapsulated by using adhesiveor another polymer or an encapsulant such as polyethylene. Thisencapsulation preferably extends throughout the ring 74 to create atight seal between the balloon 18 and the tubular body 38. Suchencapsulation allows the ring 74 to be effectively secured in place, andpromotes smoother guide wire movement through the axial lumen 20. Suchencapsulation also allows for a larger diameter for lumen 20 and fasterballoon deflations due to the improved fluid flow. It will beappreciated that essentially the same type of marker encapsulation of aring 74 can also be achieved with the embodiment of FIG. 2A where thetubular body 38 extends across the balloon 18 and through the resilientsleeve 42.

To facilitate the functioning of the releasable sealing means (valvingdevice 41) of the present invention, it is preferred that collar 46 havea generally uniform circular cross section to define a smoothcylindrical outer surface. However, as shown in FIG. 5, it iscontemplated as being within the scope of the present invention toprovide collar 46 with a slightly tapering proximal end 78 to ease theinitial engagement of resilient sleeve 42 over collar 46 as balloon 18is advanced along guide wire 22. Additionally, to provide a more securedsealing engagement collar 46 can be configured to include acircumferential groove 80. Alternatively, the proximal end of collar 46adjacent to retaining beads 54 and 56 may be provided with ahemispherical cross section for the same purposes as is shown in thealternative embodiment of FIG. 4. Similarly, beads 54 and 56 can beconfigured for this purpose.

Another advantage of the present invention is that the guide wire 22 maybe sealingly disengaged, sealingly reengaged, removed, or replaced byanother guide wire, for example, the guide wire assembly may be replacedwith a guide wire assembly having a different stiffness. In other words,the physician may want to use a guide wire which is more flexible, or aguide wire which is stiffer and more pushable. Because the lumen 20 hasa size everywhere along its length which is large enough to pass theenlarged-diameter distal end valving portion 26 of the guide wire 22,this replacement of the guide wire assembly 22 is easily accomplished.Referring to FIG. 5A, the collar 46 may also be provided with a tapereddistal end 82. This tapered distal end of the collar 46 facilitateseasier guide wire replacement.

It also should be emphasized that axial lumen 20 of the presentinventive catheter assembly 10 is configured to perform a dual role. Asshown in FIG. 2, the diameter of axial lumen 20 is greater than that ofguide wire 22, including the distal collar portion 46. By virtue of thisconstruction, axial lumen 20 is adapted to both receive guide wire 22and to conduct an inflation fluid to and from balloon 18. This dualfunction design produces an ultra-low profile balloon catheter devicewhich significantly enhances the ability of the catheter to cross verytight stenoses or to traverse particularly difficult vascular pathways.As an additional benefit, larger volumes of radiographic visualizationdyes may be injected around the tubular body 38 and through thepositioning or guide catheter (not shown) to enhance visibility of thearterial lumens during placement of the apparatus. This increased volumeof radiographic dye and improved visibility is common withsmall-diameter catheter assemblies in comparison to the larger-diameterconventional balloon catheters.

Along these lines, exemplary non-limiting dimensions for the ballooncatheter assemblies of the present invention may be as follows. Forexample, as is typical in the coronary arts, the overall length ofcatheter 14 will typically range from 120 cm to 160 cm. The axial lengthof dilatation balloon 18 will comprise approximately 1 cm to 4 cm ofthis overall length, while an embolectomy balloon will be about 0.5 cmto 2.0 cm of this overall length. Typically, dilatation balloons areavailable in stepped diameters ranging from approximately 1.0 mm to 5.0mm in 0.5 mm or 0.25 mm increments, while the stepped inflationdiameters of embolectomy balloons range from approximately 1 mm to 9 mmin 0.5 mm or 0.25 mm increments. As known in the art, these inflationdiameters are typically characterized at 6 to 10 atmospheres of pressurefor dilation. Naturally, the deflated profile of the dilatation balloonsincreases slightly with increases of the final dilation diameters.However, while the majority of prior art balloon catheters have adeflated balloon profile measuring approximately 0.04 inches indiameter, the balloon catheter of the present invention has a typicaldilated balloon profile of only 0.03 inches. Similarly, the dualfunction, single lumen design of the present invention produces atubular shaft having a correspondingly narrow profile.

Exemplary non-limiting diameters for the proximal portion of guide wire22 range from 0.005 to 0.016 inches whereas the preferred exemplaryouter diameter of cylindrical collar 46 ranges from approximately 0.012to 0.018 inches. Thus, in the embodiments of the present inventionillustrated in FIGS. 1-5A, the distal end portion of guide wire 22 isprovided with a cross-sectional diameter on the order of approximately0.005 inches and cylindrical collar 46 is formed of a polymeric materialsuch as PTFE having an outer diameter of approximately 0.016 inches anda wall thickness of approximately 0.005 inches. It should be emphasizedthat the proximal diameter of guide wire 22 need not be constant and maytaper to provide an enhanced degree of flexibility toward the distal endof guide wire 22. Guide wire 22 itself is preferably formed of metalsuch as stainless steel but also may be constructed of polymers or ofpolymer-coated metals, as is known in the art. An exemplary overall wirelength for guide wire 22 is on the order of 175 cm. The cross section ofguide wire 22 proximal to cylindrical collar 46 need not be circular tobe within the scope of the present invention. For example, generallyelliptical or ribbonlike configurations may be utilized to provide anenhanced degree of flexibility.

Also visible in FIGS. 2A and 2B, is a balloon-centered radiopaque marker76 formed as a band of dense metal, such as gold or platinum, forexample, fixed at a centered position proximal to the distal end portionof wire 22. Marker 76 can be secured to tubular body 38 in any mannerknown in the art including encapsulation, adhesives, or simplemechanical deformation, and is analogous to the marker 57 pointed outabove. Radiopaque marker 76 functions to provide the implantingphysician with a readily apparent visual reference which be viewed on afluoroscope during the angioplasty procedure. During positioning of theapparatus the surgeon simply manipulates the catheter assembly of thepresent invention until marker 76 is positioned directly adjacent orcentered in the target lesion. Because of its positioning on tubularbody 38 relative to dilatation balloon 18, when marker 76 is sopositioned, dilatation balloon 18 is positioned across the lesion aswell.

Further details of the balloon exchange or replacement procedure inaccordance with the teachings of the present invention will be discussedwith respect to FIGS. 6-16. As noted above, the exchangeableintegrated-wire balloon catheter of the present invention enables avascular physician to exchange one catheter for a second catheter alongthe pre-positioned guide wire without having to retrace the entirevascular pathway with the guide wire. As those skilled in the art willappreciate, replacement balloons produced in accordance with theteachings of the present invention need not include a guide wire. Thus,as is illustrated in FIG. 6, an exemplary replacement catheter assembly10 can be provided with its balloon 18 pre-folded over a disposablemandrel 84 and packaged in disposable balloon cover 86. Preferably,mandrel 84 is constructed of metal or plastic and approximates the outerdiameter of collar 46. Additionally, mandrel 84 may be coated withlubricating materials such as PTFE or silicone.

The cross section of FIG. 7 illustrates an exemplary folded profile ofballoon 18 for use in packaging within balloon cover 86. Viewing FIG. 6,the mandrel 84 is preferably tapered such that the diameter of themandrel at point 88 is wider than the diameter at point 90. Thistapering facilitates easier removal of the mandrel 84 and alsofacilitates reengagement of the collar 46 to allow collars 46 ofdifferent sizes on different guide wires to be fitted sealingly into thesleeve 42 of the catheter assembly 10.

Turning next to FIG. 8, in order to position the replacement catheterover a guide wire, the mandrel 84 is first removed, the catheter isflushed, and then the balloon cover 86 is removed. This allows thefolded balloon 18 illustrated in FIG. 8 to freely pass over the smallerdiameter proximal portion of guide wire 22 (not shown) as the implantingphysician advances the replacement catheter along the guide wire. Thisfolded balloon arrangement also supplies additional columnar strength tothe replacement catheter which enables the implanting physician toeasily engage resilient sleeve 42 over collar 46 to seal and inflateballoon 18, as was previously illustrated in FIGS. 3 and 4, for example.

Returning for a moment to a consideration of FIG. 1, an additionalfeature of the present invention is the provision of exit markers 92 and94 distally of the Y-connector 12 on the tubular body 38 as shown inFIG. 1. Generally speaking, exit markers 92 and 94 inform the implantingphysician that catheter assembly 10 is advancing within a tubular guidecatheter (not shown) to a position near its intended target at which thetip of the balloon 18 is about to exit a distal end of this guidecatheter. At this point the implanting physician can activate afluoroscope to assist in the visualization and final placement of theballoon 18 across the target lesion. Preferably, as illustrated in FIG.1, two exit markers are utilized. The first, marker 92 will preferablybe positioned approximately 90 cm from the distal end of balloon 18 andcan be utilized to indicate tip exit from a guide catheter positionedfor a brachial approach. Similarly, marker 94 is preferably positionedapproximately 100 cm from the distal tip of the catheter to indicateexit from the guide catheter during a femoral approach. Both markers 92and 94 may be applied to catheter 30 through printing, stenciling,embossing or the like.

Along these lines, as illustrated in FIG. 9, it is also contemplated asbeing within the scope of the present invention to provide the proximalend of guide wire 22 with its own set of visual markers, 96 and 98, toassist the implanting physician in determining that sleeve 42 is engagedwith cylindrical collar 46. For example, it is contemplated that marker98 would be positioned approximately 170 cm from tip 50 of wire 22 andwould signal that a replacement catheter tracking over the wire is aboutto exit the guiding catheter. It should be noted that this positioningis appropriate for both the femoral and brachial approaches. However,marker 96 is preferably positioned approximately 142 cm from tip 50 ofwire 22 and functions to assure the implanting physician that resilientsleeve 42 is engaged with cylindrical collar 46. In practice, theimplanting physician would visually align marks 96 and 98 with the outervisual reference formed by the proximal end of torquer 32 on Y-connector12 illustrated in FIG. 1.

Alternative exemplary embodiments of the exchangeable integrated-wireballoon catheter of the present invention are illustrated in FIGS. 10and 11. In order to obtain reference numerals for use in describing thestructure of FIGS. 10 and 11, the prior practice of referring tofeatures which are the same as, or analogous in structure or functionto, a feature depicted and described above is continued. Each of thesealternative embodiments is provided with an additional fluid conductinglumen. More particularly, the alternative embodiment of FIG. 10illustrates a catheter embodiment configured for distal infusion ofdrugs, blood or other fluids. In addition to lumen 20, this alternativeembodiment includes a second lumen 100 which serves to conduct fluidsfrom the proximal end of the tubular shaft 38 of catheter assembly 10 toits outlet port 102 adjacent to the resilient sleeve 42 on balloon 18.It should be noted that either or both lumens may be sized to sealinglyengage the enlarged distal end portion of the guide wire 22. In thisalternative embodiment, a side opening or communication port 104 isprovided in lumen 20 to enable lumen 20 to communicate with balloon 18for purposes of inflation and deflation. The alternative double-lumenembodiment of the present invention illustrated in FIG. 11 is structuredto allow the passage of blood from proximal of the balloon 18 to thedistal end of the balloon while this balloon is inflated. Thus, inaddition to dual-function axial lumen 20 catheter assembly 10 of FIG. 11also is provided with a second lumen 100 which, in turn, is providedwith at least one distal outlet port 102 and at least one proximal sideopening or perfusion inlet port 106. Inlet port 106 allows blood topassively perfuse the artery distally of the balloon 18 during inflationof the balloon. This perfusion blood flow is provided the passageway forblood to enter additional lumen 100 through port 106 and exit throughdistal port 102.

Referring now to FIG. 12, yet another alternative embodiment of thepresent inventive catheter assembly is depicted. FIG. 12 shows thedistal end portion 26 of a guide wire 22 in which an additional bandlikeradiopaque marker 108 is provided proximally of and adjacent to thecollar member 46. The marker 108 may be formed of any appropriatematerial, and is secured on the guide wire 22 so that it captures thecollar member 46 in cooperation with the coil 48. Preferably the marker108 includes a proximally disposed chamfer or taper surface 110 which isof assistance when a catheter is to engage the collar 46 at sleeve 42.That is, the tapered surface 110 of the marker leading to a chamferedproximal surface 112 on the collar member 46 virtually eliminates anypossibility that the distal end 16 of the catheter will catch on themarker or collar as the catheter advances distally along the guide wireassembly 22.

FIG. 12 also shows that the collar member 46 may be molded in place onthe guide wire 22. To achieve this molded-in-place collar member, theguide wire 22 may be placed in a mold, for example, and the polymericmaterial of collar 46 in a semi-liquid molten condition is then isforced or injected into the mold around the wire 22. For this purpose, asurface portion 114 of wire 22 would be coated with a release compound,and also may be highly polished to inhibit sticking of the injectedpolymeric material on the surface portion 114. With the proper releasecompound, and possibly with the selection of a highly polished surfacefinish on surface portion 114, and also possibly in conjunction with thecontrol of the temperature and pressure at which polymeric material isinjected to form the collar 46, the radial clearance of the collarmember 46 at surface 114 can be so small as to virtually eliminateleakage of pressurized inflation fluid axially along this interface.This virtual elimination of axial leakage is important because thevolume of the dilatation an embolectomy balloons is rather small, andthe delivery of pressurized fluid along the long and rather narrowcatheter shaft results in some considerable pressure loss during fluidflow conditions. Consequently, a leak of pressurized fluid at the collar46 can result in the balloons not being inflated as forcefully or afirmly as is desired. On the other hand, by virtually eliminating axialleakage at the interface between the wire 22 and the collar member 46,the embodiment of the present invention presented by FIG. 12 helpsassure a complete and forceful inflation of the balloon 18.

Viewing FIG. 13, a fragmentary cross sectional view of the torquer 32 ispresented. This torquer is rotationally carried at the proximal end ofthe Y-connector 12, and provides for the physician to selectively engagethe guide wire 22 in order to twist or rotate this guide wire along itslength within the catheter assembly 10. As those ordinarily skilled inthe pertinent arts will appreciate, the distal end portion 26 of theguide wire projects forwardly of the catheter shaft along a vascularpathway which the physician desires to negotiate with the catheter 10,and may be pre-curved or otherwise formed in order to assist inachieving entry into a coronary artery, for example.

Considering FIG. 13, it is seen that the torquer 32 includes a bodyportion 116 which defines an axially extending stepped through bore 118,through which the proximal portion 24 of the guide wire assembly 22extends. At its distal end, the body 116 includes an axially projectingboss portion 120 which is captured rotationally in a ring member 122.The ring member 122 threadably engages the proximal end of theY-connector 12. At its opposite, or proximal end, the bore 118 includesa larger diameter bore portion 124 leading to a tapering portion 126.Received in the bore portion 124 is a collet member 128, a part of whichis also seen in FIG. 13a. This collet member 128 is preferably formed ofmetal, and brass is the preferred metal for this use because it will notdamage the guide wire 22. This collet member 128 includes a through bore130, through which the guide wire 22 passes, and a pair of transverseslots 132 which intersect at the center of the bore 130 to proximallyseparate the collet member into four separate jaw members 134, eachhaving a pointed edge 136.

Externally, the collet member 128 includes an enlarged portion 138 whichdistally defines a tapered surface 140 engaging the tapered surface 126of the body 116. Proximally, the enlarged portion 138 defines a similartapered surface 142 which is engaged by a tapered surface 144 of a ringmember 146. The ring member 146 itself threadably engages the body 116.Consequently, tightening of the ring member 146 forces the taperedsurfaces 142 and 144 together, and forces the collet member 128 into thebore 124 to force surface 140 into engagement with the tapered boreportion 126. The result is that the jaws 134 at their pointed edge 136engage the guide wire 22, as can be appreciated by viewing FIG. 13a, toallow the physician to twist this wire by rotating the torquer 32relative to the Y-connector 12. However, as can be appreciated byviewing FIG. 13a, the guide wire 22 is of small size. For example, theguide wire 22 may be only of 0.014 inches diameter. Yet, this small wiremust be gripped along the pointed edges 136.

In order to insure that the guide wire is centered along these edges136, the torquer 32 includes a polymeric internally tapering guidemember 148. This guide member 148 is received into the bore 130 of thecollet member, and defines a funnellike entrance portion 150 leading toa tapering guide portion 152, and to a cylindrical guide portion 154immediately distal to the edges 136 of the jaws 134. Consequently, theguide wire 22 is centered in the collet member 128 and is retained alongthe edges 136 for driving engagement by these edges when the torquer 32is tightened. Also, the guide member 148 serves an additional purposewhen the catheter is advanced over a placed guide wire 22 and along thiswire to a treatment site. In this case, the proximal end of the guidewire 22 is introduced into the distal end of the catheter assembly, andthese two assemblies are relatively moved so that at the torquer 32, theproximal end of the guide wire enters first the funnellike portion 150,the guide portion 152, the guide portion 154, and then the jaws 134.Consequently, the proximal end of the guide wire 22 is guidedprogressively toward its position of centering in the jaws 134, slidesproximally of these jaws, and the guide wire 22 does not hang up on thetorquer 32.

FIG. 14 shows an alternative embodiment of the present invention inwhich a disengagement device 156 is provided on the guide wire 22proximally of the torquer 32 in order to provide for the physician animproved grip on this guide wire when the physician desires to disengagethe collar 46 from the sleeve 42 by relative axial movement of thecatheter assembly 10 and wire 22. For this purpose, the disengagementdevice 156 is formed as a tubular body 158 of elastic material whichwill afford a high coefficient of friction on the wire 22. The body 158defines a bore 160 which is sized to slidably pass the guide wire 22.Externally, the body 158 defines grip surfaces 162 at which a physicianmay manually apply gripping pressure, as is indicated by the arrows 164.Under these conditions, the body 158 is compressed such that the bore160 of the body 158 is deformed to grip the wire 22, and provides abetter grasp on this wire than the physician could achieve with just thegloved fingers. Consequently, the wire 22 is more easily and certainlymoved axially relative to the catheter assembly 10 in order to effectthe disengagement or engagement of the collar 46 from or into the sleeve42.

FIGS. 15 and 16 provide respective fragmentary cross sectional and planviews of yet another alternative embodiment of the present invention.This embodiment includes a torquer 32 which carries proximally adisengagement device, generally referenced with the numeral 166. Thisdisengagement device 166 has the same purpose as the disengagementdevice 156 seen in FIG. 14. However, the device 166 includes aproximally extending tubular boss portion 168 which is carried by thering 146 of the torquer 32. Slidably carried on the tubular boss 168 isa tubular member 170 defining a stepped through bore 172. The tubularboss member 168 outwardly defines a circumferential ridge 174, and thebody 170 at the distal end of bore 172 inwardly defines a lip 176. Thebody 170 can be forced onto the boss 168 distally of the ridge 174 byforcing lip 176 over this ridge. Once the body 170 is so disposed on theboss 168, these two features are slidable axially relative to oneanother, but the body 170 is captively retained on the boss 168. A coilcompression spring 178 is carried on the boss 168 between the ring 146and the body 170 to yieldably urge the latter toward a first proximalposition thereof.

Still viewing FIG. 15, the body 170 includes an end wall 180 throughwhich the stepped bore passes with a diameter just sufficient to passthe guide wire 22. Distally from the wall 180, body 170 also includes atubular guide portion 182 extending distally into the inside of the boss168. At its distal end, this tubular guide portion 182 defines afunnellike entrance surface 184. Inwardly, the guide portion 182 definesa proximally tapering portion 186 of the bore 172. Proximally of thewall 180, the body 170 includes a pair of opposed gripper members 188.These gripper members 188 are preferably integral with the remainder ofbody 170, and are attached thereto by flexible integral hinge sections190. Inwardly, each of the gripper members 188 carries an elasticgripper pad 192, each of which confronts the guide wire 22. Outwardly,the gripper members 188 define a textures surface 194 for manualengagement of the gripper pads 192 with the guide wire 22, as isdepicted by the arrows 196.

In use of a catheter assembly including a disengagement device asdepicted in FIGS. 14 and 15, the physician manually squeezes the grippermembers 188 onto the guide wire 22, and advances the body 170 distallyto a second position (as is indicated by arrow 198) to disengage thecollar 46 from within sleeve 42. The spring 178 insures that the body170 is maintained in the first or proximally-located positionpreparatory to this distal disengaging movement by the physician. Thus,the physician need not back off the body 170 with respect to the torquer32 preparatory to disengaging the collar 46 from sleeve 42.Additionally, the available distal movement of the body 170 is designedto insure disengagement of the collar 46 from within sleeve 42 with onlya single distal movement of the body 170. Consequently, the physiciansimply grips the members 188 and strokes the body 170 distally one timerelative to the Y-connector 12 to insure disengagement of the collar 46from within sleeve 42, and opening of the distal port 40.

FIGS. 17-34 present alternative embodiments of the present inventivecatheter having various alternative constructions for the valving device41 are shown. In order to obtain reference numerals for use indescribing all of these alternative embodiments to the valving device41, features which are the same as or are analogous in structure orfunction to features depicted and described above are referenced withthe same numeral. In cases where a feature is analogous in structure orfunction to a prior feature, but an additional aspect of that featureexists which the reader should notice, this feature is referenced with afamiliar numeral having a prime added thereto, and additionalexplanation is provided of the noteworthy variation.

Viewing FIG. 17, it is seen that the collar member 46' is tapered sothat this collar member decreases in diameter in the proximal direction.The collar member 46' is fabricated of Teflon like the collar 46 seen inFIGS. 1-5A, and FIG. 9, and is consequently very stable dimensionally.Bonded within the sleeve 42 of balloon 18 at the orifice 40 is adimensionally stable valving tube member 200. The tube member 200 may befabricated of metal, but preferably is fabricated of polyimide material.The valving tube 200 is secured within sleeve 42 by a layer 202 ofadhesive. The embodiment of the valving device 41 seen in FIG. 17 has anadvantage in that the material of balloon 18 is generally shrink tubing,or is shrunk or thermally processes from another size to the size of thesleeve structure 42 seen in FIG. 2, for example. A consequence of thisthermal processing is that the polymer material may retain a memory ofits former size and configuration.

Over time, especially with thermal cycling, the polymer material of thesleeve 42 may creep slightly back toward its former size andconfiguration. Because the valving device 41 as seen in FIG. 2 reliesfor its sealing integrity on the closeness of fit between the collar 46and the inside surface of sleeve 42, after a period of time the sealingintegrity at the valving device 41 may not be as good as at the timewhen the catheter 10 was manufactured. In other words, the catheter 10may deteriorate somewhat in a functional sense with the passage of timeand regardless of what high level of quality control is exercised in itsinitial manufacture. On the other hand, the embodiment of the presentinvention seen in FIG. 17 may enjoy an improved shelf life because ofthe dimensional stability of the tube member 200 without any significantloss of sealing integrity at the sealing device 41.

Another alternative embodiment of the present inventive catheterassembly 10 and guide wire assembly 22 is seen in FIG. 18. Thisalternative embodiment also offers the advantage of decreased relianceon dimensional precision at the collar 46 and sleeve 42, as was seen inthe embodiment of FIG. 17. Viewing FIG. 18, the guide wire assembly 22is seen to be the same as that seen in FIG. 17. However, at the sleeve42, a comparatively thick internal annular layer 204 of resilientelastic or resilient material is provided. The material layer 204 may bemade of silicone, for example, or of a material such as linearlow-density polyethylene. Significantly, the material layer 204 issufficiently thick that it is sealingly conformal to the externalsurface of the collar member 46, as is seen in FIG. 18. That is, theelastic or resilient layer 204 may contract slightly distally of thecollar 46 to form a radially inwardly extending shoulder 206. Theshoulder 206 of elastic or resilient material layer 204 in conjunctionwith the distal taper of the collar member 46 will serve to form adetent feature for the collar member 46 in the sleeve 42.

The embodiment of the present inventive catheter seen in FIG. 18 has thesignificant advantage of providing a reliable seal at the valving device41 even if the material of sleeve 42 should creep slightly with aging ofthe catheter assembly 10. That is, the material layer 204 issufficiently conformal that a seal is formed with the collar 46 even ifthe sleeve 42 supporting the material 204 has distorted or creptslightly with the passage of time since the catheter 10 wasmanufactured. In this way, the embodiment of FIG. 18 also has acomparatively high tolerance to dimensional imprecision at the valvingdevice 41.

Yet another alternative embodiment of the present invention which alsooffers a high tolerance to dimensional imprecision is seen in FIG. 19.Viewing FIG. 19, it is seen that the collar 46 is cylindrical and roundlike that seen in FIGS. 1-5A, for example. This collar 46 is sealinglyreceived into a resilient and yieldably shape-retaining annular layer208 of thermoplastic material. The thermoplastic material of layer 208helps to retain dimensional stability at the sleeve 42, and is heatsized at manufacture of the catheter assembly 10 to precisely fit insealing relation with the collar member 46. Also, in contrast to theembodiments seen earlier, the collar member 46 of FIG. 19 is carriedsealingly on a thin-walled tube member 210 which is rotationally carriedon the guide wire assembly 22. The tube member 210 forms a very smallrunning clearance with the guide wire 22 so that this tube member isrelatively rotatable, but also forms a long, or capillarylike,relationship with this guide wire so that fluid leakage between the tubemember 210 and wire 22 when the balloon 18 is pressurized issignificantly reduced. Preferably, the tube member 210 may be fabricatedfrom polyimide material.

FIG. 20 depicts yet another alternative embodiment of the presentinvention which employs a guide wire assembly 22 like that seen in FIG.19. That is, the guide wire assembly 22 includes a tube member 210 whichrotationally carries the collar member 46 upon the guide wire. However,at the sleeve 42, a tubular thermoplastic member 212 is bonded at 214and extends distally to define a sleeve section 42' which is axiallyseparated from the sleeve 42 of the balloon 18. The sleeve section 42'sealingly engages with the collar 46 of the guide wire assembly 22. Thatis, the sleeve 42' is isolated from dimensional creep of the sleeve 42by its axial separation from this sleeve 42.

FIG. 21 provides a fragmentary cross sectional view of yet anotheralternative embodiment of the present invention. This embodiment alsooffers a particularly advantageous freedom with respect to dimensionaltolerance at the valving device 41. The embodiment of the invention seenin FIG. 21 includes a tube member 210 like that seen in FIGS. 19 and 20.However, the tube member 210 of FIG. 21 carries an ellipsoid-shaped body216 of shape-conformal elastic or resilient material. The body 216 maybe formed on the tube member 210 by injection or transfer molding ofsilicone, for example. Alternatively, the body 216 may be formed from alength of silicone tubing which is adhesively bonded onto the tubemember 210. The surface 218 of body 216 is preferably treated both toimprove its abrasion resistance and to lower its coefficient offriction. An ion discharge treatment, for example, which isconventional, may be used to achieve these variations in the surfacemolecular properties of silicone material.

The ellipsoid body 216 is a body of rotation and is disposed on thetubular member 210 with its major axis parallel with the orifice 40. Ofcourse, when viewed in a direction parallel with the axis of orifice 40,the body 216 is circular in shape. Consequently, when drawn into thesleeve 42, the body 216 is distorted from its ellipsoid shape tosealingly cooperate in closing the orifice 40. This sealing cooperationof the body 216 in the sleeve 42 is effective despite dimensionalvariations and out of round distortions, for example, which may haveoccurred in or since manufacture of the sleeve portion 42. Consequently,the embodiment of FIG. 21 also offers a great freedom with respect todimensional tolerances at the valving device 41 while still achieving avery good control of fluid leakage at the orifice 40.

Still another alternative embodiment of the present invention is seen inFIG. 22. At first blush, this embodiment of the invention appears to bethe same as that of FIG. 12, for example. However, the embodiment shownin FIG. 22 includes a valving device 41 having a resilient collar member46' captured between the braze 49 and the marker 108. That is, thecollar member 46 is yieldably shape-conformal in nature. The collarmember 46' is preferably fabricated of silicone or other elastic orresilient material to be received in radial compression between thesleeve 42 of the balloon 18, and the surface of the guide wire assembly22. That is, in its free or undistorted condition, the collar member 46'defines an inner diameter slightly smaller than the local diameter ofguide wire assembly 22, and an outer diameter slightly larger than theinner diameter of sleeve 42. When the collar member 46' is received onthe guide wire assembly 22, its outer diameter may be increased slightlybecause the collar member is stretched to receive the guide wire 22.

Subsequently, when the collar member 46' is received into the sleeve 42,the collar member is radially compressed to sealingly cooperate with thesleeve 42. Also preferably, the inner and outer surfaces 220 and 222,respectively, of the collar member 46' are treated as outlined above toimprove their abrasion resistance and lower their coefficient offriction. Consequently, the collar member 46' is slidably receivableinto the sleeve portion 42 to sealingly cooperate therewith, and isrotational on the guide wire assembly 22 to also sealingly cooperatewith this guide wire. The result is that the yieldably shape-conformaland elastic or resilient collar member 46' provides a considerabletolerance to dimensional variations at the sleeve 42 and guide wire 22while still providing excellent sealing cooperation with thesestructural elements and allowing relative rotation therebetween.

Turning now to FIG. 23, yet another alternative embodiment of thepresent invention is depicted. FIG. 23 shows a guide wire assembly 22,like that described above with reference to FIG. 21, used in combinationwith a catheter assembly like described above with reference to FIG. 17.In other words, an elastic or resilient body 216 carried on a tubemember 210 upon the guide wire assembly 22 is sealingly received into adimensionally stable tube member 200 secured into the sleeve 42 by alayer of adhesive 202. This embodiment of the invention offers thedimensional stability at the orifice 40 achieved by the added stabilityof the tube member 200, and the compliant sealing nature of the elasticor resilient body 216 carried rotationally with the tube 210 on the wireassembly 22. Again, a very low level of leakage is achieved at the valvedevice 41 shown in FIG. 23, while a good tolerance to dimensionalvariations at this device is achieved with reliable sealing.

FIG. 24 shows an alternative embodiment of the present invention inwhich a guide wire assembly 22 as seen in FIG. 22 includes a resilientcollar member 46' captured between the braze 49 and the marker 108. Thisresilient collar member 46' of the guide wire assembly 22 is sealinglyreceived into a sleeve portion 42 like that seen in FIGS. 17 and 23. Inother words, the sleeve portion 42 of the valving device 41 includes atube member 200 of dimensionally stable material, such as metal orpolyimide, for example. This tube member is secured into the sleeveportion with a layer 202 of adhesive. The collar member 46 may bereceived into the tube 200 with a close fit or with an interference fit.With the interference type of fit between the collar 46 and tube 200,the collar distorts in order to be sealingly received into the tube 200.

This combination of a resilient cylindrical collar member 46 sealinglycaptured radially between the hard (dimensionally stable) outer surface114 of the guide wire and the hard (dimensionally stable) inner surfaceof the tube member 200 provides a very favorable tolerance todimensional variations of the guide wire 22 and tube member 200.

FIG. 25 depicts a particularly preferred alternative embodiment of thepresent invention in which a guide wire assembly 22 includes aellipsoid-shaped, dimensionally-stable, and layered bead member 224,which is secured on the guide wire 22 slightly proximally of the braze49. This bead member 224 inwardly may be made of metal, and may even bemade of a radiopaque metal, for example, so that the bead member 224also defines a marker for the catheter assembly 10, including guide wireassembly 22. Alternatively, a radiopaque coil or sleeve type of marker(not shown) may be provided on the guide wire 22 distally of orproximally of the bead member 224.

Carried on the bead member 224 is a first thin layer 228 ofpolytetrafluoroethylene, generally known as Teflon. Upon the layer 228,a second thin layer 230 of silicone is carried and defines an outersurface 232 for the bead member 224. The sleeve portion 42 of catheterassembly 10 is configured like that seen in FIG. 18, and includes alayer 204 of resilient polymeric material. More particularly, the layer204 preferably may be a layer of resilient silicone material, or oflinear low-density polyethylene. In this case, the dimensionally stableand internally hard layered bead 224 provides support for the layer ofsilicone 230 which sealingly engages the similar layer 204 of siliconeon the inside of sleeve portion 42. This sleeve portion 42 is generallydimensionally stable, but may be subject to dimensional creep with thepassage of time and with thermal cycling, as was pointed out above. Thecombination of the two sealingly contacting layers (204, 230) ofsilicone and the ellipsoid shape of the bead member 224 has been shownto provide a good sealing reliability, tolerance to dimensionalvariations, acceptable axial engagement and disengagement force levels,and acceptable twisting torque levels.

In fact, examples of this construction have shown very reliable sealingintegrity at the valving device 41, while also showing axial engagementand disengagement forces as well as twisting torque levels for the guidewire 22 which were well below acceptable values. Still further, thisembodiment of the invention provides a twisting torque level for theguide wire 22 with the valving device 41 closed which was at the verylower end of the torque measurement range for the conventionalinstruments which are used to test such catheter and guide wireassemblies.

FIG. 26 shows another alternative embodiment of the invention in which abead member 224' is formed on the guide wire 22 immediately proximallyof the proximal extent of the coil 48. In fact, the bead member 224' isformed of the braze 49, and for this reason FIG. 26 includes an arrowednumeral 49 pointing to the bead member 224'. Because the bead member224' is formed of the material of braze 49, the coil member 48 isimbedded in the bead member, and extends distally therefrom. Preferably,this bead member 224' will be formed of brazing material which isradiopaque, or which has radiopaque material added thereto, so that thisbead member serves as a marker for the catheter 10. Like the bead member224 seen in FIG. 25, the bead member 224' can include layers 228 and 230of Teflon and silicone, respectively. The outer silicone layer 230defines a surface 232 which sealingly engages with a layer 204 ofsilicone material carried on the inside of sleeve portion 42. That is,the construction of the sleeve portion 42 is similar to that seen inFIGS. 18 and 25. However, the embodiment of FIG. 26 may also include anexternal dimensionally stable band member 234 surrounding and carried bythe sleeve portion 42. This band 234 is preferably made of a materialsuch as a metal or polyimide, which will assist in supporting the sleevemember 42, and in resisting dimensional changes thereof, for example asmay otherwise occur with time and temperature cycling.

FIGS. 27 and 28 depict yet another alternative embodiment of the presentinvention in which a guide wire assembly 22 includes a collar member 46'trapped between the braze 49 and a marker 108. The collar member 46' isformed as a resilient disk member having an outer diameter larger thanthe inner diameter of the sleeve portion 42 of the catheter assembly 10.The collar member 46' also includes a tapering or conical peripheralportion, which is referenced with the numeral 236. As depicted in FIG.27, the free or undistorted configuration of the collar member 46' issuch that the peripheral portion 236 tapers axially and radiallyoutwardly to become thinner. The axial taper of the collar member 46' isin the distal direction so that the distal side of the collar 46' isplanar and the proximal side has a truncated cone shape.

FIG. 28 shows that when the guide wire 22 is moved proximally to pullthe collar member 46' into the sleeve portion 42, the collar member 46'distorts to be some what cup-shaped, with the cup shape opening in theproximal direction. In other words, the collar member 46' forms asealing cup with a sealing lip defined by peripheral portion 236 whichis disposed toward the interior of balloon 18. As is well known, such acup-type seal forms a dynamic seal which is responsive to applied fluidpressure to seal even more effectively, and which has good tolerance tovariations of the surface against which a seal is to be effected. Thisseal structure also offers good axial and torque values. Otherconfigurations of the collar member 46' such that it distorts from itsfree configuration into the sleeve portion 42 of the catheter assembly10 to form a dynamic lip type of seal are possible, and are within thecontemplation of this invention.

FIGS. 29 and 30 show another alternative embodiment of the presentinvention in which a collar member 46' is axially trapped on the guidewire 22 between the braze 49 and the marker 108. This collar member 46'is ellipsoid or oval in shape similarly to the embodiments of FIGS. 21,23, 25, and 26. However, while the collar member 46' is a body ofrotation similar to the earlier collar members, in contrast to theseearlier embodiments of the invention, the ellipsoid-shaped collar member46' of FIGS. 29 and 30 is configured with the major axis of theelliptical shape perpendicular to the axis of the wire 22. That is, thebody of collar member 46' is shaped so that when viewed parallel to theaxis of wire 22, it is circular, and the circular diameter is largerthan its elliptical axis seen in FIG. 29. Thus, the collar member 46'has the shape of an ovoid or saucer-shape. In its free or undistortedshape, as is seen in FIG. 29, the collar member 46' has an outerdiameter larger than the inner diameter of the sleeve portion 42. Whenthe guide wire 22 is pulled proximally into the catheter 10, the collarmember 46, distorts sealingly into the sleeve portion 42, viewing FIG.30. For this reason, the collar member 46 is allowed some space betweenthe braze 49 and marker 108 because the collar member 46 will grow alittle axially as its is distorted radially into the sleeve portion 42.

Further to the above, the sleeve portion 42 is formed to internallydefine a shallow annular and radially-inwardly opening groove 238. Thecollar member 46' will distort into the sleeve portion 42, and thenexpand partially back toward its free or undistorted shape into thegroove 238 to form a self-detenting valve structure 41 at the sleeve 42.The collar member 46' can be moved axially out of the sleeve 42 byapplication of force to the guide wire 22, but is not prone to fallingout of the sleeve portion 42 merely from handling or manipulation of thecatheter assembly 10.

FIG. 31 depicts another embodiment of the present invention in which thecatheter assembly 10 is like that seen in FIG. 2, or FIG. 21, forexample, and includes a resilient sleeve portion 42. Sealingly receivedinto the sleeve portion is a collar member 46 in the shape of a piercedsphere or ball member which is carried upon the guide wire assembly 22.However, the collar member 46 surprisingly offers a heretoforeunavailable level of precision, low friction engagement with thecatheter shaft, uniformity of sealing fit in the sleeve 42, and sealingintegrity at the sleeve 42, with attendant uniformity of selected axialengagement/disengagement force, and with low rotational torque valuesfor torquing of the guide wire rotationally relative to the cathetershaft.

The collar member 46 is formed of Al₂ O₃, which is synthetic ruby orsynthetic sapphire gemstone. Of course, natural gemstone may also beused, if desired. Further, the gemstone need not be limited to ruby orsapphire. However, the Applicants have determined that synthetic ruby orsapphire gemstone members are available in shapes appropriate for use ascollar member 46, and at a comparatively low cost. This material offersa very low coefficient of friction so that the engagement force for thecollar member 46 into sleeve 42 is controllable and very predictable byprecise formation of the size of the sleeve 42 relative to the size ofthe collar member 46. Also, the inherently low coefficient of frictionof the synthetic ruby or sapphire assists in controlling this engagementforce to a low level with a sufficient distortion of the resilientsleeve 42 to insure good sealing integrity at the valve device 41.Further, pierced synthetic ruby and sapphire ball members arecommercially available, and are made of synthetic ruby or sapphire foruse as small precision bearings in such devices as mechanical watchesand instruments. These bearing ball members are available at areasonable cost and with very high precision. For example, commerciallyavailable ball members may be had with a sphericity tolerance of only0.000005 inch. The size tolerance for these ball members is similarlysmall.

With this high level of size and shape precision for the collar member46, the sleeve portion 42 may be precision formed, and the collar member46 will sealingly fit into this sleeve member with a preciselypredictable engagement/disengagement force being provided. Further, theinner diameter of such pierced ball members is similarly precise so thata sealing but relatively rotational fit of the collar member 46 on theguide wire 22 can be achieved, if desired. Alternatively, the interfaceof the inner bore of the ball member 46 and the outer surface of theguide wire 22 may be provided with a layer or sleeve (not shown) ofresilient material sealingly closing the space between the ball 46 andguide wire 22. For example, silicone, Nylon, and low densitypolyethylene may be used to coat the inner diameter of the bore in ball46, or the congruent section of the guide wire 22, so that the two aresealingly related when the ball 46 is placed on the wire 22. Thesematerials offer a low enough coefficient of friction, however, so that alow rotational torque value for the guide wire 22 relative to theremainder of the catheter is still provided.

The inner diameter surface of the sleeve portion 42 may also be made ofor may be coated with thermoplastic or thermoset material with anenduring dimensional memory so that dimensional stability of the sleeveportion 42 is maintained. The synthetic ball member which forms thecollar 46 will inherently have such a low coefficient of friction at itspolished outer surface with the sleeve portion 42 that the collar member(ball) 46 may be adhesively attached to the guide wire 22, androtational freedom of this guide wire will be provided by sliding (whilestill sealing) engagement of the collar member 46 within sleeve portion42. This adhesive attachment of the collar member 46 directly to theguide wire 22 eliminates any possibility of fluid leakage between thecollar and guide wire.

FIG. 31 also shows that the sleeve portion 42 may also be formed with acircumferentially and radially inwardly extending stop rib 239. Thisstop rib 239 is disposed proximally of the collar member (ball) 46 sothat this collar member cannot be inadvertently pulled through thesleeve portion 42. The collar member 46 can be forced past the stop ribby the application of sufficient pushing or pulling force at theproximal end of the guide wire 22, so that the guide wire assembly canpass through the lumen 20 of the catheter 10. This feature of stop rib239 at the sleeve portion 42 is of importance and greatly aids in theability of a physician to reengage the valve ball 46 into the sleeveportion 42 without the need for fluoroscopic guidance. That is, thephysician can simply feel at the guide wire 22 when the valve ball 46has entered the sleeve portion 42, and when this valve ball encountersand is stopped from further relative proximal movement by the rib 239.

Viewing now FIG. 32, another alternative embodiment of the catheterassembly 10 is fragmentarily depicted in which the sleeve portion 42carries internally a layer of thermoplastic material 208, like that seenin FIG. 19. However, the layer of material 208 seen in FIG. 32 is formedto include a screw thread 240. On the guide wire assembly 22, the collarmember 46 is non-rotationally carried on the distal portion 26. Thiscollar member 46 is formed with an external screw thread 242 which isthreadably engageable into the thread 240 with a slight interference fitto form a sealing-tight engagement between the collar 46 and the sleeve42. Although it is not depicted, it is apparent that a square shoulderon the collar member engaging onto a square seat of the sleeve portion,or a tapered shoulder engaging onto a tapered seat, for example, couldbe defined by a slightly enlarged distal portion of the collar member46, which would seat on a distal end surface of the catheter 10. Thistype of sealing cooperation of the collar 46 and sleeve 42 is notdepicted in the drawing Figure, and is believed not to be necessary inorder to achieve a satisfactory level of sealing integrity for theballoon catheter of the present invention. The screw threads 240 and 242may be formed with a straight triangular configuration, as depicted, andwith or without a slight interference fit to effect a seal.Alternatively, the screw threads 240 and 242 may be formed with a slighttaper, like pipe threads, to effect a seal as the collar 46 is threadedinto the sleeve 42. Alternative thread configurations which may functionsatisfactorily at the valving device 41 include straight or taperedacme-form threads, and multi-start threads.

The embodiment of the present invention depicted in FIG. 32 has aparticular advantage in that a disengagement apparatus, like that seenin FIGS. 14 and 15, is not required for the catheter assembly 10including guide wire assembly 22. In other words, the physician canrotate the guide wire as necessary (using a torquer if desired) toeffect steering of the catheter assembly along a vascular pathway, withthe collar 46 threadably received in the sleeve 42. A sufficient extentof threaded engagement is provided that the collar member 46 is notinadvertently unthreaded from the sleeve 42.

This threaded engagement of the collar 46 into the sleeve 42 at thedistal end of the catheter assembly 10 has the additional advantage ofinsuring the physician that manipulations of the catheter assembly, suchas pushing this assembly along a guide catheter or through a tightlesion, for example, will not inadvertently cause the collar 46 todisengage from the sleeve 42. When the physician is ready to disengagethe collar 46 from within the sleeve 42, the torquer 32 may be used tomake a sufficient number of rotations to the guide wire assembly 22relative to the remainder of the catheter and in the direction tounscrew the collar 46 distally from the sleeve 42. Once thisdisengagement of the catheter assembly 10 from the guide wire assembly22 is accomplished, the physician will be able to feel the relativelyfree relative axial mobility of these two assemblies. A catheterexchange, if necessary, can then be accomplished as described above. Thereplacement catheter assembly will need to be configured with a matchinginternally-threaded sleeve portion 42 to sealingly cooperate with thecollar portion 46 of the guide wire assembly 22.

FIG. 33 depicts yet another alternative embodiment of the presentinvention, which is particularly preferred. This embodiment includes asleeve portion 42 of valving device 41, which sleeve portion 42 includesa layer 204 of material which is at least somewhat elastic or resilient.As pointed out in connection with the description of FIGS. 18, and 25,this layer 204 of elastic or resilient material may be formed ofsilicone or of linear low-density polyethylene, for example. On theguide wire assembly 22 is adhesively and sealingly secured a collarmember 46 of synthetic ruby or sapphire, as was described above withrespect to FIG. 31. That is, an adhesive, as is indicated by the arrow244 secures and seals the spherical collar 46 to the wire 22. Theundistorted inner diameter of the elastic or resilient layer 204 is lessthan the outer diameter of the collar (ball) 46 by a selected amount.

Accordingly, the collar 46, when forcefully drawn into the sleeveportion 42 causes an elastic deformation of the layer 204, as isindicated by the arrow 246. Preferably, the deformation of the materialof layer 204 is elastic deformation, and is maintained well below thelevel of deformation necessary for plastic deformation of this material.For example, with linear low-density polyethylene for the layer 204, adeformation of about 37 percent is necessary before the material deformsplastically (i.e., permanently). Accordingly, the deformation 246 at theinterface of the collar (ball) 46 and the layer 204 of elastic orresilient material is maintained at a level of about 6 percent to about8 percent. This level of elastic deformation of the elastic or resilientlayer 204 is only a fractional portion of the deformation which would benecessary to effect permanent deformation of the layer 204 and issufficiently low that the collar (ball 46) may easily be turned withinsleeve 42 with a low required torque while still maintaining a goodseal. That is, the ball 46 may be rotated within sleeve 42 with a lowtorque value which prevents wrapping of the balloon 18 about wire 22,while still maintaining a very good sealing integrity at the interfaceof the ball 46 and sleeve 42. Also, the collar (ball) 46 can easily bedisengaged from and reengaged with the sleeve portion 42. Tests of thisembodiment of the invention have shown good sealing integrity whensubjected to an internal pressure of up to 25 atmospheres, even withrepeated engagements and disengagements of the ball 46 into the sleeveportion 42. Mathematical analysis further shows that this embodiment ofthe present invention should have good sealing integrity with aninternal pressures up to 95 atmospheres, or more. Because the expectedinflation pressure for the dilatation balloon 18 is only 15 to 25atmospheres, the surprising and unexpected combination of excellentsealing integrity and low disengagement/reengagement forces, along withlow guide wire torque values achieved by the use of the syntheticgemstone collar (ball) 46, and a layer of elastic or resilient material204 within the sleeve portion 42 is well beyond the requirements for thecatheter 10.

FIG. 34 depicts yet another alternative embodiment of the presentinvention, which embodiment also has similarities to those embodimentsdepicted in FIGS. 18, 25, 31, and 33. In the embodiment shown in FIG.34, the sleeve portion 42 internally carries a layer 204 of elastic orresilient material. However, in order to achieve a higherengagement/disengagement force into and out of the sleeve portion 42 forthe collar 46, this collar is made with at least two of the piercedsynthetic gemstone balls (referred to as 46' and 46") arranged in seriesand adjacent to one another. The proximal one (46') of the pair ofgemstone balls is adhesively secured to the guide wire 22 by a layer ofadhesive 244, as was explained with reference to FIG. 33. However, thedistal one (46") of the two gemstone balls is axially positioned withfree relative rotation on the guide wire 22 merely by the adjacent braze49 on one side, and by the other adhesively-secured ball 46' on theother side of the ball 46".

Both of the balls 46', 46", elastically distort (arrow 246) the layer204 of elastic or resilient material. However, the sealing integrity ofthe proximal ball 46' is so good that the distal ball 46" is not neededfor additional sealing security. For this reason, no effort is made toseal the bore of the ball 46" with the guide wire 22. The second anddistal ball 46" is provided in order to increase the level of axialforce required on guide wire 22 to effect engagement and disengagementof the collar portion 46 (balls 46' and 46") of the valving device 41,while maintaining a desirably low torquing value for the guide wire 22.This latter objective is accomplished because the distal ball 46"contributes to a desired increase in the axial force, but is freelyrotational on the guide wire 22 so that torque values for rotation ofthe guide wire 22 are not increased by the second ball member 46". Also,this feature provides the desired level of tactile feel for engagementand disengagement of the collar 46 into sleeve 42, while preserving thegreatly reduced or eliminated wrapping of the balloon about the guidewire 22 when the guide wire is torqued relative to the catheter shaft.Thus, when the valving device 41 is closed by forceful engagement of theballs 46' and 46" into the sleeve portion 42, torquing the guide wire 22slides the ball 46' at its sealing engagement with the layer 204. Theguide wire 22 rotates freely within the distal ball 46", and thetorquing level for the catheter 10 is about the same as the embodimentshown in FIG. 33.

Thus, the apparatus of the present invention provides an exchangeableintegrated-wire balloon catheter that can be positioned within avascular pathway by a single vascular physician. Because the apparatusof the present invention provides the maneuverability of a fixed-wiredilatation catheter coupled with the benefits of a catheter of ultra-lowprofile, it can be quickly and easily maneuvered into position acrosslesions that are critically narrowed and which are shaped irregularly.Following expansion of the balloon and dilation of the lesion thecatheter of the present invention can be disengaged from the distal endof its guide wire and retracted back from the lesion to allow thephysician to visualize blood flow while retaining guide wire accessacross the lesion. If necessary, the physician can advance the balloonand reengage the distal end of the guide wire to reseal the balloon forpurposes of re-inflation. Alternatively, while leaving the guide wire inplace the physician can completely remove and replace the ballooncatheter with one having alternative dimensions which, in turn, can besealingly engaged with the distal end of the guide wire for inflationpurposes or a conventional over-the-wire catheter may be advanced alongthe wire. Lastly, in cases of acute re-closure the guide wire of thepresent invention can be utilized to direct a perfusion catheter intoposition. The guide wire may also be removed, reengaged or replaced.

In closing it is to be understood that the embodiments of the inventiondisclosed herein are illustrative of the principals of the invention andthat other modifications may be employed which are within the scopethereof. Thus, by way of example, but not of limitation, the resilientsleeve may be configured to extend into the interior of the dilatationballoon, as opposed to the outwardly-extending configuration of thereleasable sealing means illustrated. Any of the modifications describedherein may also be applied to an embolectomy balloon catheter inaccordance with the present invention. Accordingly, the presentinvention is not limited to that precisely as shown and described in thespecification.

According to further aspects of the present invention, which are setforth in the following paragraphs, the invention may be seen to includeand to comprise: a balloon catheter and guide wire combination includinga flexible, elongate, small-diameter guide wire having a distal endvalving portion of comparatively enlarged diameter, and ahighly-flexible distal end portion joining with the remainder of theguide wire; a flexible elongated tubular shaft having a proximal end anda distal end portion defining a distal end and at least oneaxially-extending fluid-conducting through lumen adapted to receive theguide wire therethrough; the distal end portion of the tubular shaftbeing adapted to sealingly cooperate with the enlarged-diameter distalend valving portion of the guide wire in a selected position of thelatter to distally close the lumen; and the tubular shaft at the distalend portion thereof including an expansible balloon member having aproximal end and a distal end and defining a portion of the throughlumen, the proximal end of the balloon member attaching to the remainderof the tubular shaft adjacent to a distal end thereof and defining thedistal end portion for the shaft.

Also, the invention may be seen to include the subject matter set forthin the paragraph above, and further including the balloon catheterwherein the through lumen is of a size sufficient to pass theenlarged-diameter distal end valving portion of the guide wire.

Still further, the present invention may be seen to include the subjectmatter set forth in the above paragraphs, and further wherein theelongated tubular shaft and the expandable balloon are formed ofresilient polymeric material.

Also, the balloon catheter of the above paragraphs may include thepolymeric material of the elongate tubular shaft being selected from thegroup comprising homopolymers and copolymers of: polyvinylchloride,polyethylene, polyolefin, fluoropolymer, polyamide, polyester,polyimide, and polypropylene.

Additionally, the balloon catheter described in the paragraphs above mayinclude the polymeric material of the expandable balloon being selectedfrom the group of materials including: latex, kraton and silicone.

In yet another aspect, the present invention may include the ballooncatheter as described in the paragraphs above, and wherein the catheterfurther includes a wrapping of filamentary material about one of theproximal end and the distal end of the balloon.

Still further, the present balloon catheter may be seen to furtherinclude a coating of binding material over the wrapping of filamentarymaterial.

Another aspect of the present balloon catheter according to the aboveparagraphs provides the coating of binding material including a urethanematerial.

According to a comparatively broad aspect of the present invention, theballoon catheter described in the paragraphs above may include the guidewire including an elongate wirelike portion extending between a proximalend thereof and the enlarged-diameter distal end valving portionthereof, and a distal highly-flexible coil portion disposed distally ofthe enlarged-diameter distal end valving portion, the wirelike portionand the distal end highly-flexible coil portion being joined to oneanother to define a braze joint, and the tubular shaft including adistally-extending circumferential portion which is radially congruentwith the braze joint to shield the latter when the enlarged-diameterdistal end valving portion of the guide wire is received sealingly intothe distal end portion of the tubular shaft.

The balloon catheter set forth in the paragraph immediately above mayinclude the distal end portion of the tubular shaft including one of: aresilient sleeve member extending from the distal end of the balloon andattached to the distal end of the tubular shaft, the sleeve member beingdimensioned to slidingly and sealingly receive the enlarged-diameterdistal end valving portion of the guide wire; a resilient sleeve memberincluding a proximal portion received within the elongate shaft at adistal end portion of the latter, the elongate sleeve member alsoincluding a distal portion extending distally beyond the shaft and beingdimensioned to sealingly receive the enlarged-diameter valving portionof the guide wire; and a dimensionally stable sleeve member receivedwithin or circumscribing the distal end portion of the catheter shaftdistally of the balloon to dimensionally stabilize the distal portion.

Still further, the balloon catheter described above may include thedistal end portion of the tubular shaft including an internal layer ofelastic or resilient material which is dimensionally conformal to andsealingly engageable with the enlarged-diameter distal end valvingportion of the guide wire.

Another aspect of the balloon catheter of the above paragraphs includesthe enlarged-diameter distal end valving portion of the guide wireincluding a collar member carried upon the guide wire, the collar memberhaving a larger diameter than the remainder of the guide wire proximallyand distally thereof; and the collar member having a shape selected fromthe group including: cylindrical, conical, ellipsoid, disklike,spherical, ovoid, and saucer-shape.

Still further, the balloon catheter described above may include thecollar member being shape-retaining and dimensionally-stable incharacter.

As described above, the balloon catheter of the preceding paragraphs mayinclude the collar member being of yieldably shape-retaining elasticcharacter to vary in dimension in response to forces applied thereto,the collar member in its free undistorted condition defining an innerdiameter smaller than the outer diameter of the guide wire congruentwith the collar member, and the collar member being elastically expandedonto the guide wire to sealingly prevent leakage of inflation fluid fromthe balloon between the collar member and the guide wire; and the collarmember in its free undistorted condition defining an outer diameterwhich is larger than an inner diameter of the tubular shaft distal endportion, the collar member being distorted sealingly into the distal endportion of the tubular shaft distal end portion.

The balloon catheter described above may include the collar memberfurther carrying a coating selected from the group including:polytetrafluoroethylene and silicone.

This balloon catheter may include a torquer for use to rotate the guidewire of a balloon catheter and guide wire combination, the torquerincluding a collet portion defining a through passage passing the guidewire, the collet member including a plurality of jaw featurescooperatively engageable with the guide wire to transmit torque thereto,means for selectively engaging and disengaging the jaw features from theguide wire, and a guide member received in the through passage of thecollet member and centering the guide wire relative to the plurality ofcooperable jaw features preparatory for engagement therebetween.

This torquer may include the guide member including a funnellikeentrance portion disposed distally of the catheter for guiding aproximal end of the guide wire into the jaw features, a cylindricalguide bore portion located immediately distally of the plurality of jawfeatures, the cylindrical guide bore portion being sized to closely passthe guide wire and to center the latter relative to the plurality of jawfeatures, and the guide member further including an elongate taperingguide bore portion intermediate of the funnellike portion and thecylindrical guide portion.

According to another broad aspect of the present invention, the ballooncatheter and guide wire combination may comprise: a flexible, elongate,small-diameter guide wire having a wirelike proximal portion, and adistal end valving portion of comparatively enlarged diameter; aflexible elongated tubular shaft having a proximal end, a distal end,and at least one axially-extending fluid-conducting inflation lumenadapted to receive the guide wire therethrough; an expansible balloonmember having a proximal end and a distal end, the balloon memberincluding a distal end orifice, and cooperable sealing means at thedistal end orifice for sealingly cooperating with the enlarged-diameterdistal end valving portion of the guide wire to selectively open andclose fluid communication through the distal end orifice; and theballoon catheter and guide wire combination further including proximaldisengager means for selectively moving the guide wire axiallyrelatively to the tubular shaft to engage and disengage theenlarged-diameter distal end valving portion of the guide wire with thecooperable sealing means.

This combination of balloon catheter and guide wire as described in theparagraph above may include also the proximal disengager means includinga body carried upon the guide wire proximally of the tubular shaftmember, the body defining a through bore movably passing the guide wire,and means for frictionally engaging the guide wire for axial movement inunison with the body relative to the tubular shaft.

Still further, this catheter and guide wire combination may include thedisengager body being of shape-retaining yieldably elastic character,the means for engaging the guide wire including the body outwardlydefining grip surfaces for manually effecting distortion of the bodyinto frictional engagement at the through bore with the guide wire.

Additionally, this combination of catheter and guide wire may includethe proximal disengager means including a body juxtaposed with aproximal portion of the guide wire, the body including a through borepassing the guide wire, and a pair of confronting gripper membersreceiving the guide wire therebetween, the gripper members inwardlydefining a surface portion for frictional engagement with the guide wireand outwardly defining a manually-engageable surface portion forreceiving manual force to effect frictional engagement of the grippermembers with the guide wire.

The combination described in the paragraphs above may also include amember carrying the disengager body for axial relative movement with orrelative to the guide wire, and further including yieldable resilientmeans extending between the member and the body for yieldably urging thelatter proximally to a first position preparatory to distal movementtogether of both the body and the gripped guide wire to a secondposition decoupling the enlarged-diameter distal end valving portion ofthe guide wire from sealing cooperation with the tubular shaft.

Still further, the present invention includes a balloon catheterassembly, the balloon catheter assembly being usable with an elongateguide wire assembly having an enlarged distal end valving portion, theballoon catheter assembly including an elongate catheter shaft carryingan expansible balloon adjacent to a distal end thereof and defining adual-purpose lumen both for communicating inflation fluid to the balloonand for passing the guide wire assembly, a distal orifice having aninner diameter and communicating outwardly of the balloon, and selectivesealing means cooperable with the enlarged distal end valving portion ofthe guide wire assembly for in cooperation with the enlarged-diameterdistal end valving portion of the guide wire assembly sealingly closingthe distal orifice to retain pressurized inflation fluid within theballoon and for allowing selective opening of the distal orifice inresponse to axial relative movement of the guide wire assembly, theselective sealing means including one of a dimensionally-stable meansisolated from or resistive to dimensional change of the balloon at thedistal orifice for reliably effecting sealingly cooperating with theenlarged distal end portion of the guide wire to sealingly close thedistal orifice, or dimensionally conformal means for reliably effectingsealing cooperation with the enlarged-diameter distal end valvingportion of the guide wire assembly despite dimensional change of theballoon at the distal orifice.

The balloon catheter assembly described immediately above may includethe dimensionally-stable means including a dimensionally-stable tubemember disposed at the distal orifice, the dimensionally stable tubemeans defining an inner diameter which is either sized to sealinglyreceive and cooperate with the enlarged diameter distal end valvingportion of the guide wire assembly, or which receives a portion of thedistal orifice and is secured thereto to stabilize the inner diameterdimension of the distal orifice for sealing cooperation with theenlarged-diameter distal end valving portion of the guide wire assembly.

Also, the balloon catheter assembly as described in the paragraphsimmediately above may include the dimensionally-stable tube member beingsecured at the distal orifice either within the distal orifice by asurrounding layer of adhesive, or around the distal orifice by a layerof adhesive or a material bond within the tube member.

The balloon catheter assembly of the above paragraphs may also includethe dimensionally-stable tube member being fabricated of a materialselected from the group including: metals, thermoplastic and thermosetpolymers, and polyimide.

This balloon catheter assembly described above may also have the layerof thermoplastic material and the enlarged diameter distal end portionof the guide wire each define one of a pair of cooperative screw threadsurfaces, the screw thread surfaces threadably and sealingly engagingone another when the enlarged-diameter distal end valving portion of theguide wire is sealingly cooperating with the selective sealing means.

Still further, this balloon catheter assembly of the paragraphs abovemay include the distal orifice being defined by a distally extendingsleeve portion of the balloon, the dimensionally-stable means includinga distally extending tube member having a proximal portion sealinglyreceived in the sleeve, and a distal portion disposed distally of thesleeve, the distal portion of the tube member defining a boredimensioned for sealing cooperation with the enlarged-diameter distalend portion of the guide wire, and the distal portion of the tube memberbeing isolated from dimensional changes of the sleeve portion of theballoon.

The balloon catheter assembly described in the paragraphs above may alsoinclude the selective sealing means including dimensionally-conformaland shape-retaining yieldable elastic sealing means compensatory fordimensional change of the balloon at the distal orifice for sealinglycooperating with the enlarged distal end valving portion of the guidewire assembly, thereby to sealingly close the distal orifice despitedimensional change of the balloon at the distal orifice thereof, andwherein the elastic sealing means including a circumferential andaxially extending layer of elastic material carried within the distalorifice for sealing cooperation with the enlarged distal end portion ofthe guide wire.

This balloon catheter as described above also may have the elastic layerformed of a material selected from the group including silicone, andlinear low-density polyethylene.

Still further to the above, the balloon catheter described immediatelyabove may include the layer of elastic material being elasticallystrained by entrance into the distal orifice of the enlarged-diameterdistal end valving portion of the guide wire assembly, the elasticstraining of the elastic material being limited to a fractional portionof the strain level which would effect plastic deformation of theelastic material, thereby to preserve sealing engagement of theenlarged-diameter distal end valving portion of the guide wire assemblywith the elastic material at the distal end orifice despite repeatedsealing engagement and disengagement therewith.

According to another aspect of the present invention, the invention mayinclude an elongate guide wire assembly including an enlarged-diameterdistal end valving portion, the guide wire assembly being for use with aballoon catheter assembly which includes an elongate catheter shaftcarrying an expansible balloon adjacent to a distal end thereof anddefining a dual-purpose lumen both for communicating inflation fluid tothe balloon and for passing the guide wire assembly, the ballooncatheter assembly also including a distal orifice communicatingoutwardly of the balloon and selective sealing means at the distalorifice for sealing cooperation with the enlarged-diameter distal endvalving portion of the guide wire assembly to close the distal orifice,the elongate guide wire assembly comprising: an elongate wirelike shaftportion; a highly-flexible distal end portion joined to the elongatewirelike shaft portion; and a collar member carried upon the wirelikeshaft portion proximally adjacent to the highly-flexible distal endportion to define the enlarged-diameter distal end valving portionthereof.

This guide wire assembly described in the paragraph immediately abovemay include the guide wire assembly including means securing the collaraxially relative to the wirelike shaft portion, the securing means beingselected from the group including: adhesive material securing the collarmember to the wirelike shaft portion; the collar member being formed incompression upon and bonding to the wirelike shaft portion to securethereto; the collar member being shrunk from a previouslyenlarged-diameter size onto the wirelike shaft portion to compressivelygrip the shaft portion; a fine-dimension tubular member which with acongruent section of the wirelike shaft portion cooperatively definesessentially a zero-clearance radial fit therebetween thereby to preventleakage of pressurized inflation fluid from the balloon through theclearance; a bandlike member physically securing to the wirelike shaftportion and axially confronting the collar member to position the latterrelative to the shaft portion with the bandlike member defining achamfer surface disposed proximally to guide entrance of the collarmember and the bandlike member into the distal orifice; and the bandlikemember being formed of radiopaque material so that the bandlike memberserves as a marker for the position of the guide wire.

This guide wire assembly described above may include the collar memberbeing of a shape selected from the group including: disklike, spherical,ellipsoid, ovoid, conical, and saucer-shape.

Still-further, the guide wire assembly described above may have thecollar member formed of a material selected from the group including:metal, polymers, elastomers, and gemstone including synthetic sapphireand ruby.

Also, this guide wire assembly, as described, may include the collarmember including a pair of pierced synthetic gemstone beads carried onthe wirelike shaft portion, a proximal one of the beads being adhesivelysecured to the shaft portion of the guide wire assembly, and the distalone of the beads being freely relatively rotational on the shaftportion.

Further to the above, this guide wire assembly of the paragraphs abovemay include the collar member carrying outwardly thereon a coating ofmaterial selected from the group including: polytetrafluoroethylene, andsilicone.

Finally, this guide wire assembly may also include the collar membercarrying outwardly thereon both a coating of polytetrafluoroethylene,and a coating of silicone over the coating of polytetrafluoroethylene.

We claim:
 1. A balloon catheter and guide wire combination comprising:aflexible elongate tubular catheter shaft having a proximal end and adistal end, a distal end portion adjacent to and defining said distalend, and at least one axially-extending fluid-conducting through lumen,said tubular shaft in said distal end portion including an expansibleballoon member in fluid communication with said through lumen, saiddistal end portion including a sleeve portion disposed distally of saidfluid communication of said balloon member with said lumen; a flexible,elongate, small-diameter guide wire assembly slidably received into andpassable through said lumen, said guide wire assembly having arespective proximal end and a respective distal end, a valving portionof comparatively enlarged diameter adjacent to said distal guide wireend being sealing engageable with said sleeve portion in a selectedrelative axial position of said guide wire assembly to said cathetershaft, whereby fluid injected into said lumen at said proximal catheterend is effective to inflate said balloon; and said guide wire assemblyvalving portion including a collar member which is sealingly engageablewith said sleeve portion, said collar member being formed withdimensional precision of a material selected from the group including:natural gemstone, synthetic sapphire gem stone, and synthetic rubygemstone.
 2. The balloon catheter and guide wire combination of claim 1wherein said collar member includes a pierced bead of gemstone.
 3. Theballoon catheter and guide wire combination of claim 2 wherein saidpierced gemstone bead is adhesively secured to said guide wire assembly.4. The balloon catheter and guide wire combination of claim 2 whereinsaid collar member includes a pair of said pierced gemstone beadscarried adjacent to one another on said guide wire assembly, one of saidpair of beads being adhesively secured to said guide wire assembly, andthe other of said pair of beads being freely relatively rotational onsaid guide wire assembly.
 5. The balloon catheter and guide wirecombination of claim 1 wherein said distal end portion of said tubularshaft includes an internal layer of elastic or resilient material whichis dimensionally conformal to and sealingly engageable with said collarmember of said guide wire assembly.
 6. The balloon catheter of claim 5wherein said layer of elastic or resilient material is elasticallystrained by entrance into said sleeve portion of said collar member ofsaid enlarged-diameter distal end valving portion of said guide wireassembly, said elastic straining of said elastic or resilient materialbeing limited to a fractional portion of the strain level which wouldeffect plastic deformation of said elastic or resilient material,thereby to preserve sealing engagement of said enlarged-diameter distalend valving portion of said guide wire assembly with said elastic orresilient material at said sleeve portion of said catheter shaft despiterepeated sealing engagements and disengagements therewith.
 7. Theballoon catheter and guide wire combination of claim 1 wherein saidsleeve portion includes a radially inwardly extending stop rib which iseffective to resist passage of said collar member of said valvingportion therepast but which will allow such passage upon the applicationof sufficient pushing or pulling force to said guide wire assembly. 8.The balloon catheter and guide wire combination of claim 1 wherein saidsleeve portion at said distal end portion of said tubular shaft includesa dimensionally-stable sleeve member received within or circumscribingsaid distal end portion of said catheter shaft at said sleeve portionthereof to dimensionally stabilize said sleeve portion.
 9. The ballooncatheter assembly of claim 8 wherein said dimensionally-stable sleevemember is fabricated of a material selected from the group including:metals, thermoplastic and thermoset polymers, and polyimide.
 10. Theballoon catheter and guide wire combination of claim 1 wherein saidelongated tubular shaft and said expandable balloon are formed ofresilient polymeric material.
 11. The balloon catheter and guide wirecombination of claim 10 wherein said polymeric material of said elongatetubular shaft is selected from the group comprising homopolymers andcopolymers of: polyvinylchloride, polyethylene, polyolefin,fluoropolymer, polyamide, polyester, polyimide, and polypropylene. 12.The balloon catheter of claim 10 wherein said polymeric material of saidexpandable balloon is selected from the group of materials including:latex, kraton and silicone.
 13. The balloon catheter and guide wirecombination of claim 1 wherein said guide wire assembly includes anelongate wirelike portion extending between said proximal end thereofand said enlarged-diameter distal end valving portion thereof, and adistal highly-flexible coil portion disposed distally of saidenlarged-diameter distal end valving portion, said wirelike portion andsaid distal end highly-flexible coil portion being joined to one anotherto define a braze joint, and said tubular shaft including adistally-extending circumferential portion which is radially congruentwith said braze joint to shield the latter when said guide wire assemblyis in said selected relative axial position to sealingly engage saidenlarged-diameter distal end valving portion of said guide wire withsaid distal end sleeve portion of said tubular catheter shaft.